It helps a lot with the fans, I notice I'm much less fatigued after a long day with th QC15s vs the telex 850s, if you compare the 2, I'd consider the 850's ANR to be totally worthless.

Sunglasses aren't too bad, defiantly wearable, but since the earpad cushions go around the ear, there is a slight increase in noise while wearing sunglasses because they break the "seal" around your ear. That being said, I don't hesitate to use sunglasses if I need them.