GPS is pretty much instant [with the Case-Mate Pop]? Not for me:
http://youtu.be/pVh96ffr6z0?hd=1
The case offers good protection but will look VERY weathered after a week. I also did not appreciate the horrid GPS performance my phone was exhibiting with the case on. No matter how you cut it, the Pop will be riddled with micro-scratches. I kept my phone on a stack of paper or a foam mouse pad and kept it off any abrasive/hard surfaces and it still looked terrible after a week. It looks very pretty when new, but it will certainly not stay that way for long.
The case can also be difficult to take off, so if you need to get to the battery often, you'll be annoyed sooner than later. When removing it, it's difficult not to put pressure on the phone itself, which I did not feel comfortable with. Not only that, taking the case on/off frequently will cause the grey silicon lining to separate from the plastic casing around the corners especially. If you keep your phone in your pocket, like most people do, it will also accelerate the wear of the grey rubber lining around the corner and edges to the effect of what a rubber band looks like when you stretch it before it breaks and allow it to return to its normal state.
I contacted Case-Mate about the terrible performance of my Pop case and they stood by their product and customer service. They gave me a brand new Barely There and a Case-Mate Tough Case for my DHD at no additional cost. They didn't even ask me to return the Pop. They simply wanted to see pictures of the case and the video (linked above) of the GPS performance. They said they would hand off the video to their development team for investigation. Mind you, there are many cases that cause a phone to exhibit poor GPS performance, but in my case it was completely unacceptable.
I'm currently using the Barely There that Case-Mate gave me and I really like it. The protection level is certainly not as good as the Pop or Tough Case, but the GPS performance is better (still afflicted though) and the profile of the Barely There is fantastic if you keep your phone in your pocket or chest pocket.