Installer quality vs film brand, what actually matters more?

[honoriagrimble]

I've been going back and forth with a couple of shops and noticed something odd. One place quoted me way less but when I asked what film they use they got weirdly vague about it. Another shop charges more but was upfront about everything and even showed me samples of different films. I started reading about best film brands, according to Paint Protection Film and it got me thinking that maybe the brand is only half the story. A top tier film installed badly is probably worse than a decent film installed by someone who actually cares. So for those who've been through this, did you pick based on the film name or the installer's reputation? And is there any way to tell if a shop is actually good before you hand over your car and a big chunk of change?