I put the Knight Design 1" lowered pegs on today, after a friend with a metal grinder removed a 3/8 in. "triangle" from the rear corner of each, that would have hit the exhaust ccovers.
The peg R+R itself went without a hitch, 5 minutes each. The problem solving came when attempting to re-adjust the foot-to-control interfaces. An extra 10 minutes for the shifter, an extra hour for the brake. The brake readjustment was complicated by the way the control arm attaches to the master cylinder plunger. I could not turn the lock nut itself (to shorten / lengthen the throw), I had to turn the control arm pivot, because the locknut is embedded in that thing. That means removing and disassembling the entire rear brake assembly from the cycle frame. There's no bleeding required when finished, but be sure to double check the setup before tightening everything back down.
It's worth the effort tho, I can already feel the difference in ergo's, and like it.
BTW, Knight Design offers a "pointy, jagged" type of peg footing and I bought that. It's really going to take some getting used to it, and I think mebbe I would not do it again. The execution of the points is too tall / jagged. I think a "finer" granularity of the "jagged-ness" would be better, for me. Just my .02