I've owned a Nexus 4 16GB model for a month now. It is my first smartphone. My previous Android experience was limited to playing around on my wife's DroidX2 and installing a custom ROM for her. I view myself as technically proficient, love linux, command lines, etc.... you get the idea.
My main motivations for buying the N4 were:
Google device, gets the latest updates with no delay
Gives a pure Android experience, no bloatware
Developers device, gets the latest custom ROMs
Plenty of carrier/prepaid SIM options
High performance for the price (quad core, 2GB RAM)
My doubts about it:
Small internal storage
Inaccessible battery
Glass back made me nervous
When I unboxed the phone, the first thing I noticed is how beautiful the back glass is. It's not too flashy, as some of the first photos on the web made it appear. It feels very sturdy, and is very light. The whole phone has a slick feel to it, and I'm glad I bought the OEM bumper for it. The bumper adds little bulk, and it enhances the feel and grip just the right amount. If I didn't know better, I would probably feel it was part of the phone.
I bought a StraightTalk T-Mobile SIM. Downloaded a template to cut it to fit the microSIM tray of the Nexus 4. No problems and had it running and the APN setup in minutes. Vanilla Android is great, but I love tinkering, so I visited xda-developers and read up on things. Used WUGfresh's root toolkit, unlocked, rooted, flashed Paranoid Android ROM, with Franco's kernel.
Everything I've tried with this phone runs fast, haven't had any issues at all. Even the StraightTalk prepaid service is working fine in my location. It helps that I'm in the middle of Savannah, GA. T-Mobile coverage is good throughout the area.
I feel like I'm rambling, it's late. If you've got specific questions, I'll do my best to answer them.
edit: dropped it only once. Hardwood floor from 4 foot counter. Not sure what side it landed on, but it doesn't have any scratches or cracks. I keep it in my pocket or on a desk at all times, so my worries about the glass are mostly unwarranted.