Yes - I installed them this past Spring. Previously, I had a B6 with Progressive springs and a Hayabusa shock. I did not revalve the B6, but did play with the fork oil weight. I got a B12 last Fall and added Racetech springs (0.95) right away (with 10W oil)- after a few months, I added the Gold Valves and 5W oil (stock oil is 10W). The B12 handled WAY better than the B6. The difference around town is more subtle - you will notice more plush response out of the front end. I noticed most of the difference during a three day weekend to Deal's Gap/Blue Ridge parkway - the B12 was very steady in turns and soaked up mid corner bumps very well during aggressive riding- I would recommend. Just be sure and get all your tools sorted out ahead of time (an in-lb torque wrench is tough to find) and debur (use emory paper too) the holes in the tubes (the ones you create when you drill out the stakes). Also, use white lithium grease (or seal grease if you have) to lube the O rings - or you will cut them -I had to order more from Racetech as I chewed up the two that came with the kit.
Jay