I'm actually trying out a bunch of cases from Spigen and Seidio this month. Here's my two cents so far:
- My wife has the Seidio Active case for her S III, and that is a great case. Great drop protection and the kickstand is actually pretty handy. I assume the S4 case has identical build quality. I expect the Surface will add less bulk than the Active, but it's really a matter of personal preference.
- Currently I'm trying out the Spigen Crimena (leather pouch) and the Neo Hybrid. (In case anyone's curious, the Crimena is a tight fit, and the phone in the Neo Hybrid definitely will not slide inside the Crimena. I'm hoping the Ultra Thin Air case will.)
- Neo Hybrid looks great. The rigid plastic band around the edge of the phone looks glossy, but it is actually the part of the case that improves the grip. The black matte back of the Neo Hybrid is actually pretty slippery. I agree with Eric618. I'm guessing that this case will provide minor drop protection only.
- I've also got the Slim Armor and Ultra Thin Air cases from Spigen on order from Amazon. And will probably try out the Seidio cases as well before I decide on one and return the rest.