Ya know, I've talked to many friends who swear they dont have any scratches (and dont use protectors), and in a matter of a fraction of second of picking their phone up, I find fine hairline scratches (yeah, I'm alot of fun at parties LOL). GG holds up very well... and is quite tough, but really, a particle of sand between your finger and the glass, you may not notice, but its scratched. in a year or so, you might have enough to notice.
OK so.. Steinheil Ultra Nano.. Just got them. I'm familiar with all their products, excluding the new glass ones.
the Ultra Nano is really really thin (about 1/3 of others, at 5mil). It's got a surprisingly high difficulty for installation, and I'm really good at these... I can lay down an iPad sheet without a bubble or repositioning (yes, I'm bragging about it LOL). Not only do you have to line up the notches and watch the rounded corners of the glass, but its very flimsy and doesn't hold its shape as you lower it down on the screen like some others. I always use tape to position a screen protector. I put a tab on each corner and lower it down. Well, the ultra nano will fold and stick, making it alittle more complicated. Add to that, its very very thin, so if you lay it down and need to reposition, you must take great care not to crease it.
that said, its very quality material.. optics are awesome. Feel... eh.. gonna take some getting used to. My last Stienheil were the Ultra Crytal on a Note. these Nanos have a bit more resistance than the Crystal and Oleophobic line. Then again, maybe my hands are just dry right now.