Quoted:
is the griffin survivor better than the otterbox defender?
I don't know the exact answer because I don't have either yet. But for my experience on my iPhone case I LOVE my otterbox however my only complaint is the "rubber" cover becomes loose over time and comes off. From a few things I found the rubber fits tighter and for longer on the griffin. The plastic looks a bit "thicker" on the otter box then the griffin especially in some areas (corners) from what I can tell in videos and pictures. However, the rubber is thicker so it looks like that makes up for it in those places (most of the stuff I found was from last version griffin, except one video of a guy showing the new one he got. So they could have improved the plastic. I just wouldn't be able to tell unless I had two side by side.
They look like they both have their positives and negatives both look about the same quality wise and protection wise with drop protection from what I can tell. I just like that I can button up the griffin and protect it from rain/dust. So all personal preference.