Pretty Darn awesome
First off setting this derailleur up was a snap.
1. Set the high and low stops
2. Pull cable pretty tight and cinch the bolt
3. Dial out the barrel adjuster until shifts are snappy.
4. Go on a ride confident your shifting will be awesome.
For some reason the SRAM Red was a lot less finicky to setup than my other non-Red derailleurs. Maybe its the engineering but it might be worth spending the extra $ if you maintain your own bikes, cause working on the good stuff is easy.
Other than that this thing is light, sculpted, elegant, and my drivetrain is quieter now (must be the jockey wheels)
Minus one star for the silly price tags on this stuff, if it breaks I will have to sell my son's braces.