I've got an original set of Avid mechanical discs [essentially BB7s] that are over 6 years old and going strong. I also have a new set that are performing well. The BB7 is my go to brake if I want to run discs.
Dang, dude. Six years is a good long loyal time for a piece of equipment. Best I've had was a 7-speed Shimano group that I abused for over 12 years. Gave it away in very good working order last year.
Anyway, great to know about your BB7s.
Schweet. I'll wander over...