I have used the Otter box Defender series on all my phones up to now and it has been awesome. Not a single broken phone, and I do drop them from time to time.
With that said, there have been quite a few complaints ascot the Edge version of the Defender boxes: the screen protector is thick and so some people have had problems with screen sensitivity.
Currently, I am using Armorshield screen protector, which is a plastic sheet. The big issue is that if it isn't placed perfectly, then your case may cause an edge to peel up, which is annoying, to say the least.
It should do a fine job of protecting against scratches, but it doesn't have quite the touch-sensitivity that my Galaxy S4 in the Otterbox Defender has.