The buttons are properly usable again and it feels smaller and lighter in hand.
No regrets, I haven't properly dropped it yet but I love the phone again, it's not just another phone in a bumper case.
Sits a little proud (on top of the Sony pre-installed protector) but it at last makes my phone feel premium. It feels just like the Gorilla glass on my Nexus 4 used to, there is no loss of sensitivity and the oleophobic coating works as well as the Nexus S. I have the full (side and rear) protection and have ditched my official bumper. The phone is so much nicer to look at and to hold, but is probably a little more vulnerable.