The Spigen does NOT cover the curved parts of the glass, however, it comes pretty close. In fact, these are the only protectors which I have seen which actually come as far as possible, before the screen actually starts to curve. Most protectors come WAY short of the curved glass (they are literally just a small horrible square), but the Spigen comes as close as possible.
I haven't tried the Zagg wet install ones however, I have used the Skinomi ones - which are pretty good (if you don't mind the 'orange peel' effect which ALL wet install protectors end up with).