Wanted to just write a quick review. Just got this item, so can't comment on actual protection. But when I was looking for a screen protector for my s3 I didn't see any that commented on if this would work with cases or cover for the phone.
I use an Otterbox Commuter Case for Samsung Galaxy S III - Glacier
and am happy to report that it fits fine with the case. There are absolutely no areas where the protector peels or anything similar. It, coupled with this protector makes the phone feel indestructible!
Installing the protector was a bit of a pain in the ass (can be attributed to me having never done this before.) I tried the steamy bathroom method and it didn't quite work for me. Left the shower on for 10 ish minutes and went in thinking "this is gonna be easy". It wasn't. You need VERY steady hands as well as a dust free environment. Due to my, possible, arrogance I wasted the first cover. The second went on better. Once on you can hardly even see it's there. The second time round I didn't get a single air bubble or anything, of which I was very proud. It does feel very robust, and I'm sure it'll protect against scrapes and things. Will update this review after a couple more weeks/months of use.
There was a very nice surprise of some sweets in the parcel. Very nice touch. And from what I've read on the reviews here, the owner of MediaDevil, Callum, seems very caring of his customers, I'm sure that if I ever encounter any issues with the cover Callum will be happy to help. Which can only be a bonus in this day and age.
All in all, I'd recommend this cover over any others for the points I mentioned above. The customer care especially would make me buy again if I needed to.
I just glad I don't need to do this often, and I hope to get a good few months of loyal service out of this protector.