I hate the bumper.
You can use barely any headphones with it, and no third party dock connector accessories fit hardly - i.e iPhone headunit cables, iTrips, car chargers.
Utter crap. No reason at all to make the holes around the ports so tight.
I bought two cheap gel bumpers off eBay, one's lime green and one's orange, and I'm quite happily using them while my bumper sits in a drawer. Considering I could buy SIX of these eBay ones for the same price that's a pretty poor show.
Main reason I bought them is that the cable on my Alpine headunit wouldn't fit with the bumper on, and taking the bumper off and putting it back on between two and four times in an average day was actually starting to damage my phone.
So they must have realised people would be taking this thing on and off, but do they make it easy/safe to repeatedly put on and remove? No way, they use hard plastic for the interior, and just to be sure they give it sharp edges inside as well. Nice one :/
The bumper is better quality of course, but fit is no better - they're the same amount 'loose' at the sides if you pull the sides. It's just that it's plastic/rubber instead of just gel rubber, and the build in buttons look good.
I still prefer the eBay ones to be honest.