I have the 32gb black running on T-mobile here in Florida. Fortunately I live in an area where I have great LTE coverage. Coming from a Galaxy Nexus, I have been very pleased. The only real issue I've had is with several apps that aren't 4.4 compliant yet. Call quality has been very good both with the built in speaker and with headphones (the Samsung earbuds I get with my Nexus S several years ago).
The phone is FAST!!! Start up time is much faster than my GNex and my screen looks amazing. The one thing I don't like is the headphone jack being on the top of the phone. My past phones, that jack was on the bottom.
Battery life is excellent for me. Currently, my phone has been on 9hrs 27mins today. Screen on time is just a tad over two hours and talk time (I do a LOT of conference calls) is just over three hours and I still have 53% battery left. I have WiFi, Data and Bluetooth on and run mostly on wifi.
Last night, I switched from Dalvik to ART (JIT vs. AOT). Took a while for it to do whatever the phone needed to do, but I swear it runs even faster. They say ART is still in beta, but seems to work fine for me. I also run Nova Launcher, 8SMS and a few other specialized piloting applications on the phone as well as the normal stuff (1Weather, FB, SoundHound, IMDb,Chromecast, Flipboard, blah, blah, blah). I have a lot of "Google" services disabled (Books, Movies, Magazines, Games, G+, Hangouts, News, Picasa uploader, Quickoffice and the Koren KB's).
I'm 6'8", 280lbs and have fairly large hands. The size of the phone has taken some getting used to. My GNex in an OB Defender case fit me good. I'll be much happier with this phone once my iBlason Armor case gets here from Amazon. The N5 is thin and light. I really need the case.
Overall, I'm very happy with the phone. This phone is my primary source of communication (voice and text). I don't do much gaming on it. I have my N7 for that. I'm glad I got it and look forward to a few years of good service out it.
If you have some specific questions, please ask and I'll do my best to answer them.