The Samsung hardware, fetters and chains excepted, is tolerable. The software is crap.
Yes, per Wikipedia:
"All Nexus devices feature an unlockable bootloader[3] to allow further development and end-user modification.[4]"
https://en.m.wikipedia.org/wiki/Google_Nexus
http://android-developers.blogspot.com/2010/12/its-not-rooti...
http://www.engadget.com/2011/11/03/galaxy-nexus-gets-rooted-...
Note that this still does you comparatively little good if you don't have CyanogenMod to put on it. Mind, I didn't say "no good", I said "little good".
It's the CyanogenMod dev team at Cyanogen Inc who've been impacted by the layoffs. There's still the independent effort, but it's lost a major employer and investor.
Even if CyanogenMod suffers, there's plenty of other open-source Android versions out there. Unfortunately finding a clear, unbiased comparison of them is even harder than it is for different Linux distros. :(
I got there in the end, and I'm pretty sure most newer phones can be flashed in far easier ways.
It's actually massively soured me on Android (as well as several vendors, yes, specifically you, Samsung) as a result.