I've been using the original Instinct m800 since launch day and it's been a pretty solid and durable phone.
I picked up the Instinct HD at Best Buy four days ago and have been using it since. I'll just start off by saying that I am not impressed in the least and the phone will be going back in a few days.
Let's start with the build quality of the device. I've read the first few reviews ranting how the device is well built, but I don't see it. First, the front display is covered in what appears to be glass, but is not as cool to the touch or as solid feeling as the piece on an iPhone or iTouch. The shiny stuff surrounding the display is just plastic, like on the original m800, unacceptable in my opinion for a phone of this price range. Holding the phone in your hands, it's immediately apparent that this is lighter than the m800; it feels less solid, and given it's larger footprint and size, feels almost toylike when you pick it up - Definitely not a fan here. The rubbery texture on the rear of the device feels cheap and is not as well made as it is on the m800, and also leads to a lack of grip. Speaking of which, the contoured shape of the phone leads it to continuously slip around in my hand and is awkward at best to hold. In sum, it doesn't feel as well made or as solid as the original Instinct m800, which I've taken to hell and back.
Secondly, let's talk about the feature upgrades.
To start, the camera is a joy to use. It has all of Samsung's usual camera tricks (smile shot, face detection, anti-shake, etc.), and they have finally gotten down the autofocus times to useful levels. Phones like the older A800 and even newer Samsung's like Verizon's u940 still suffer from horrendous shutter lag. In comparison, the m850's dual stage shutter button instantly focuses with a slight press and then saves immediately upon pressing down again. The dual LED (?) flash is more than I could ask for. Every setting is adjustable, and the camera UI itself is taken from Samsung's digital cameras (right down to the scene mode selection). As far as photo quality itself - well it's OK, but doesn't seem to compete with the company's best camera sensors from overseas. HD video recording is shockingly good, but I have no idea when I'd use this. So the camera really is this phone's claim to fame.
Now, the display. Well, it's nice and vibrant, and uses 16 million colors, but for some reason I can't help but wonder why Samsung didn't use one of their magnificent new AMOLED displays on the "HD" Instinct. Just go look at the beauty on the SCH-u960 Rouge...it's unreal. In comparison, the m850's screen is probably as good as an HVGA display can look. Text is noticeably more shark, pictures pop more, and the display is brighter than the m800, and finally no more pixels to be seen, but I'm still left a little cold for the price tag.
Now, the UI..Well, they didn't really do much. You can finally change the backgrounds, and there are 4 color themes (black, purple, blue, green), but this is not worthwhile for reasons I will discuss a little later. You can customize the location of the menu tiles, and there is a new "list" setting for each screen. In this mode, the phone will display tiny text for new emails or text messages, mildly intriguing I suppose. Samsung has also added a "slide to unlock" bar when you unlock the display, but I found it unintuitive at best. First, it is hard to use and doesn't respond well. Second, it is located at the top of the display and cannot be moved, so it cuts off your wallpaper (the bottom would have been more usable, a la iPhone), and third, it looks like a tacked on afterthought. Since you can still hold to unlock the phone in the normal Instinct fashion, there should be an option to make this garbage disappear. There is also an "app manager" in the pull down status menu, thought I am not sure why the hell it's there since the only application it will ever show running is the music store (more on that unimproved disaster later). Evidently this is another afterthought. Oh, and one minor (and weird) thing is that the bottom row of lit buttons will only illuminate each key for the screen you are on...if you are in Phone, the phone light will go out and the button doesn't function, only the home button will illuminate; at the main home screen, only the phone light will illuminate; In a menu, all three are lit. This is interesting but I am indifferent to its usefulness.
In sum, the UI feels like the same exact thing from the Instinct with minor additions, but nothing of any real useful substance. Sure, it looks better on the higher resolution display, but it's still the same thing at the end of the day.
Next, we have the new sensors: To start, the phone has a proximity and light sensor, as well as an accelerometer. The proximity sensor works well, the display turning off when you put it up to your face a la iPhone (and many other Samsung/LG touchphones as well), and comes on when you take the phone away from you face...this only functions in an active call. Then we have the ambient lighting sensor, which like the iPhone's, is pretty useless...the phone should dim the screen to the lowest level it does when you force it to "always dim" in a pitch black room. The reality is, it dims it slightly but not to my liking. This feature is useless. Finally, there is the accelerometer, which works well in the camera and Opera applications.
Next, I'll discuss the speed of the interface and the associated screen responsiveness. To put it lightly, both are a trainwreck at best.
First, we have the capacitive touchscreen. Sounds great on paper, but Samsung should stick to making their resistive screens. They failed with capacitive on the first SCH-u940 (glyde), and then resorted to sourcing the later units with a resistive...you'll understand why when you use the Instinct HD. Engadget and PhoneScoop seem to have some delusional misconception that the original m800 Instinct had an unresponsive touchscreen, but the reality is that it is probably one of the best on the market. By comparison, the Instinct m850 is sketchy at best with it's responsiveness. Typing is a chore, as is navigating through a list, which has gone from great (m800) to choppy.
This issue is compounded by the fact that the UI speed itself is miles worse than the m800. Push "main", wait, push "settings", wait. To top it off, the now capacitive lit buttons on the face of the phone are difficult to use and don't respond quickly or with any certain amount of accuracy. Both make for a frustrating experience when trying to do much of anything. Oh, and if you can believe it, the onscreen keybord is slower and even more laggy than on the Instinct...pathetic, just pathetic.
To put it simply, this is no iPhone display even if it's "capacitive". It's gotten worse from the m800 and made for an annoying user experience. I have no idea why the reviews out there online are stating otherwise (that the display is responsive), but it's simply not true.
Next, we have the new onboard applications (twitter, facebook, myspace). These are all blatant afterthoughts. Facebook takes 2 minutes to load upon launching it, and the others are choppy and unrefined as well. What a joke. The youtube app is again a link to m.youtube.com
Equally demoralizing is the same exact, laggy, ugly, and slow Sprint music store. Sprint TV, however, has been vastly improved interface wise (lists actually move in a fluid motion), but the picture quality is still trashy.
Then we have the Opera Mobile browser. It's ok, but I still like opera mini better (faster)...and guess what...Opera mini has a big bar of virtual directional buttons and softkeys when you load it up on this thing. So you only get 2/3rds of the screens real-estate at best...I can't figure out how to turn this off...
Finally, I'll delve into call quality and volume and battery performance...
The speaker has been relocated to the rear of the phone, and it's a huge improvement for the speakerphone.
RF performance is the same as the Instinct m800, which is excellent.
Now the battery has thus far been pretty bad. It's 1440mah I believe, but with the wifi activated, it lasts less than half a day. Without the wifi, it still seems worse than the m800. The phone lives on the charger.
Further, the vibrating function is vastly improved
Speaking of wifi, which I didn't get to earlier. This is another joke of a feature. As far as I can tell, there is no way to force the phone to use wifi. If there is any sort of Sprint 1xev-do or 1xrtt connection, the phone uses it over the wifi. I've gotten it to use wifi when the connection was zilch, but then as soon as it found that zero bar 1xrtt, there is was using that again.
All in all, I am not impressed with this phone. It neither feels or acts like a $250 phone in this day and age of smartphones, and generally just feels like something that the first Instinct should have been last summer (yes, there were 5mp sensors out then, too). Like I said, it's going back to Best Buy and I'm waiting for October 11 (the Hero retail release AND the Samsung/Sprint CTIA m900 Instinct Q launch announcement). This phone is not anything worth buying in my opinion, and I like Samsung phones.
I hope you found this review helpful if you are considering buying this phone.