[One (M7) General] gaspernemec:
Coming from S3 and I can say it is 200% improvement....mine S3 was sluttery at best, tried mostly every rom out there, only setup that worked somehowly fast/smooth was odexed/fully debloated stock with custom kernel. However, I have given up on my S3, which cost me a fortune btw, and started looking for new phone. Firstly I wanted to get NoteII, but than I went for HTC ONE. I am still blown away by its speed, smoothnes and that feeling of lightness (it feels like phone does everything with ease, difference from samsungs, those feel like they struggle to open even most basic apps like dialer-I did little test there, compared my ONE with sisters NoteIII, which should run faster due to stronger chipset. Guess what? ONE is faster with opening apps after restart-when they arent in ram, and even from ram-apps tested were dialer, messaging, camera,....). First thing i fell in love with was landscape keyboard, its soooo easy to input text. Than there was sense, I fell in love with it, its so classy, totally different from toyish touchwiz. Blink feed didnt cut it at first, but than i started to scroll it and got used to it, now i like it. Another great thing is design, ONE looks and feels fantastic, everyone, even htc haters admit it is best looking phone out there. Screen is one of the best if not the best on market, despites the fact Im coming from amoled screen, it was suprisingly easy to adopt to more nstural colors, and i was tired of seeing pentile jaggies everywhere (believe mr or not, they are noticeable even on s4s 400+ppi screen, especially on orange color), htc ones screen is sharp, i tried many times to actually see pixels-with no sucsess, even on curves. Sound quality is superb, headphoes sound sounds fantastic on stock and even better with purex and musicbox. Boomsound kinda dissapointed me at first, it wasnt as loud as I imagined, but it was just feeling, since it produces much wider sound, than other single speaker phones, those simply shout and crack, meanwhile one actually plays it. Camera quality is good, but not excellent. It is very good on low lightning conditions and even in good light/or perfect picture focus, but if you miss that, it isnt as good as 2013 flagship should be.

Now things I dislike:

Camera: as I said, it is good on low light, but it doesnt catch enough details on good light, dont get me wrong, it is useful for facebook,..., but it wont have enough sharpness for anything bigger, except in perfect conditions

Button placement: it takes some time to get used to buttons, power button is distant, but when you get used to it, its not a problem anymore, same goes for home and back buttons (i dont know why they didnt put multitask button as standalone, instead of htc logo, since it is really "funny" doubke tapping home button or holding it for menu OR why didnt they simply implent software buttons, which would even help to decrease bezel)

Quite big bezel: not really disturbing, but important for asthetics, phone would look sooo much better without that extra bezel

Heat: it heats quite alot, not really big problem, but all that heat is energy from battery, which could be used in better way

EDIT: sorry for posting whole novel here under negatives... :)