Well I just joined the Nexus club too after 2 trips to the Verison store to compare screens and other features. If anyone is 'on the fence' regarding this maybe this will help. I'm keeping the Bionic as both a spare and for hard-use scenarios where I'd either be worried about damage or fringe area reception - like the beach, camping, worksites (areas with a lot of sand and grit), etc. The Bionic is a tank with the extended battery, Gorilla Glass and a TPU cover and I can simply swap the SIM between the Bionic and Nexus to switch phones.
Here were my concerns:
Screen - seemed much dimmer with grayish white levels instead of the practically blinding white levels on my Bionic due to the extra white pixel in the Bionic Pentile screen design.
You get used to the slightly dimmer screen and suprisingly, the unit I got seems brighter and with better white levels than the demo at verizon. Side-by-side with the Bionic, the height of the screens is a tie when you factor in the soft button panel, but the Nexus is notably wider than the Bionic's and in some full-screen apps the soft button panel 'hides'. I'm not sure about screen hardness. Never had a problem with my naked Bionic's screen but have heard about scratches being a problem for some people with the Nexus. Thinking about a tempered glass screen protector, still checking into that.
Performance -I know benchmarks don't matter that much but as a general reference they have some validity. The Quadrant and Linpack scores were sorta troubling...so I unlocked/rooted the phone,*and started with the XenonHD Jelly Bean ROM and things improved somewhat. Quadrant scores settled into the mid-2400's range. Updated to the 12-8-15 XenonHD update, as it now allows overclocking...with the right kernel. Then really bit the bullet and got the Franko kernel app from Play ($3)and let it flash my kernel automatically and WOW. Overclocked, and I use the term lightly since the Nexus' OMAP 4460 CPU was designed to run @1.5Ghz, I chose the 384mhz GPU kernel and set the CPU to 1420Mhz. Pretty conservative and actually UNDER native specs. Quadrant now runs in the mid 3500s range, linpack in the mid to upper eighties, Antutu of 7467, SmartBench 2012 productivity over 3000 and sunspider at 1537.0. The ROM and kernel will let me go to 1.8Ghz, although I don't think I will go there LOL. Not sure what this will do for the battery life, but the kernel/ROM combo has some pretty granular voltage/clockspeed settings so some fine-tuning may be in order. I'm prepared to get an extended battery if need be.
Eronomics - without some sort of case the Nexus seems like a drop waiting to happen. I opted for the Black TPU case at Verizon (Note: they're MUCH cheaper through Amazon) and the phone is not only easier to grip, but like most TPU cases, there's a small lip that overlaps the edge of the screen so if you lay the phone face-down it's resting on TPU, not the screen. By the way, Verizon incorrectly lists these as silicon. You can easiy tell the difference between TPU and silicon because it feels stiffer and barely stretches.
Build Quality - say what you will about the Bionic's locked bootloader and other issues, Motorola has excellent build quality. I was not impressed with the feel of the Galaxy S3, although supposedly made of polycarbonate, it feels insubstantial. The Nexus to me at least feels better in-hand than the GS3. Not quite as good as my Bionic, but solid nonetheless.
Storage - OK this was a biggie. No SD card slot. Even with the 32GB Nexus it still sort of bugs me BUT - once rooted and fiddled with, USB On The Go works, at least with Stickmount, a free app by Chainfire (one of the XDA techno 'demi-gods'), and I can plug in a three dollar USB-OTG cable and access flash drives and supposedly other USB devices. Kludgy to be sure, but an acceptable alternative storage solution.
So... this whole thing started when I heard Best Buy was offering the Genex for FREE with new account or upgrade. My other line had an upgrade available and I was sort of saving it , thinking about the GS3-but that would have been 200 bucks and times are tight. So I got the Genex thinking I would quite possibly return it if I couldn't lay my concerns to rest, and get the Galaxy S3 instead. Not Going To Happen. While the performance specs aren't as good as say the HTC One or the GS3, they are pretty good. But the real deal-clincher is that I really like that it's a Nexus device. I got Sooo tired of the endless update delays on the Bionic (despite being on the .232 ICS leak) and locked bootloader crap. Now I can be relativly assured that I will get timely OS updates. Verizon realeased their JellyBean binaries shortly after JB was released and there are now incremental OS updates already available (clouds part, heavenly chorus ensues). No more waiting for carriers to get around to approving updates and piling on their bloatware.
I wonder if Google didn't finally tell Verizon to fish-or-cut-bait with regard to the Nexus program after the ridiculous fiasco in ultimately getting the Nexus up*to the 4.04 update. Coincidentally, shortly after that Google announced the Nexus direct from the Play site program and the intent to further expand Nexus offerings, so I wonder what the back and forth was like between Google and Verizon.
Hope this helps those who are still weighing the Nexus Pros and Cons.
