I personally love the Neo Hybrid case and have been a fan of the design since the first one i bought for my Note II. Its slim, doesn't add much bulk, and gives a bit of protection, though not a lot. It's easy to install and fits the phone perfectly, all the holes seem to line up nice and neat. I am using it with a MIME glass screen protector and it still fits over the edges without issue. Im unsure whether they will release just the frames or not, but if they do it makes changing the look of your case easy and inexpensive.
The only issues i have with the case are that it does make it even harder to get the USB cover open, the protection it adds isn't enough to protect from a decent fall, and the plastic buttons feel loose and rattle a bit.
A couple other things to note are that the case does add a small lip to protect the camera and Spigen did also put a taper in the rubber below the heart rate sensor to allow clearance so you could still use it. That being said, i have larger hands and still have a hard time getting a reading without fussing with the sensor quite a bit.