Now I have my own 2017 XT brakes I can chime in with own experience rather than watching friends smoking Shimano pads.
From the disc rotor dilemma thread
Alpinum wrote:
180/160 on my short travel trail bike. It's quite new so I'm just running the OEM Brakes. Killed the original organic Shimano compound on the rear just yesterday. Glazed, squeek, not much performance left. This was on the rear. The rear pad has fins... will change to swissstop pads and larger discs.
Bigger discs on the way. Pads were severly glazed.
The only thing you can do if you love riding very steep and long descends with out a break is bigger discs. Rather do that then invest in 4 piston brakes. They get smoked too with too little discs. I just got a pair 200/180 mm for 20 CHF.
Now go figure how this compares to pads with fins...
In my POV fins are a waste of money. If you have issues with overheating brakes then 1. learn how to brake properly. If you master that and still have issues, get larger rotors and any pad you like will likely do.