Okay so I used my second piece, here's what happened after 2.5 months:
The glass was chipping at 2 corners (not a big deal), but recently bubbles began to form. On Saturday, for some reason it cracked all around the bubble. This was from the same batch as the first screen. As such, I replaced it with the 3rd screen (the one they sent me a few months back) and it definitely looks like there were some changes made to the manufacturing. The ambient light sensor cut was different, and it seems to be sticking better at the edges. We'll see how this one holds up.
Also, XtremeGuard has great service. I emailed them again about this issue, and they promptly replied to send another one my way, all free of charge.