It is different - but I like it. The screen is beautiful. The interface is different - not bad or good - just not what I'm used to. I do like the home button though - long press to get Google Now and double press to get S-Voice. There are quite a bit of Samsung apps that I'm enjoying. S-Health is nice, but there is a widget that shows how many steps you have taken in the day - and for some reason it motivates me to walk more. The Smart Remote is very complete - including remote codes for my WD-Live box and drop down for every room I have in the house. There is another app call BeepNGo - where you can put all your club/membership cards on (Tom Thumb, AutoZone, etc...). The screen will show the bar code and it can be scanned at the register. There are coupons in that app as well.
NFC actually works. Verizon activates ISIS - which is like Google Wallet. There are deals on it and where it can be used. Google Wallet works as well - which is nice. I've heard in the past that Verizon locked it down - so it is nice to see it up and running.
Camera is absolutely amazing IMO. It struggles a bit in low light, but it really is a champ everywhere else. The software allows you to download more picture taking options - including now the sphere mode. The effects sometimes take a little time to correct - but at least the camera works to it's fullest (yes - taking a little jab at ReZound camera issues in Kit-Kat)...
Everything I wanted in a phone - it has it. I managed to drain the battery one day of really heavy use - but otherwise the battery does a great job. I'll be getting a spare at some point.
The root is still not found - and as a result I'm missing the native WiFi Tether - which was really cool to have on the ReZound. There is a way to get the connection using the USB cable and PDA+Net software - but it really is a backwards hack to get it up and running.
A lot of people complain about the look & feel of the phone. Quite honestly - I don't care for - the first thing I did was buy a case for it. If I had the M8 - I'd do the same thing. I will always want a cover to keep the phone from getting scuffed and better protect the screen and camera lens.
Bottom line - I like the phone a lot. I'm not going to trade the replaceable battery for the ability to root (which I feel is the current trade off at the moment).