I just put on the curved crystal (had a nano previously). It is amazing. It covers completely, did not lift at all and the cut outs are very precise. Yes, take care to line up the top edge when starting out (follow their instructions). I got the first one on perfectly straight with no dust or bubbles. It wasn't too hard.
This one is truly invisible, no edges to be seen because it covers the screen all the way to the edge of the device. I like the coverage and way it disappears better than the nano I had. The generic TPU case fit over it at the edge just fine (I used care around the edges when putting the case back on).