What's your experience with this type of protection? Have you used it for a while? I hate light scratches and swirls, does this prevent that?
Yup, so far it's been great as long as I don't drop the phone. I've been using these since the Note 5 and every time I've traded in, my phones look spotless, plus if the film gets too scratched, it's very cheap to replace...although I usually get a 2-pack, IQ shield offers lifetime replacements in case the film fails, is damaged, or even if you screw up the installation.
I have, however, dropped an S7 Edge and it cracked the screen (granted, I did throw it more than drop it, but still). And film edges do tend to get dusty/dirty, but so do the glass ones.