It's easy to unlock HTC Bootloader if it's supported in there bootloader tool, only around 5-10minutes. It's not fully s-off though like the HTC One X but its possible to flash kernels and roms.
Nexus 5 32gb Black / OmniROM / Faux Kernel Latest
Nexus 7 32gb 2013 / OmniROM / Faux Kernel Latest
Previous Phone (2013): Nexus 4, HTC One, Sony Xperia Z, Samsung Galaxy S4 i9500, Nexus 4
Previous Tablet (2013): Nexus 7 (2012), Nexus 10, Samsung Galaxy Note 10.1