I have them on my N15, they've probably done about 20,000 miles...and the only thing that has happened is on the N15 a part of the axle is slighly different to the B14 and that has rubbed on the rears and left a deep scratch on both. But that's only cosmetic and obvisously you won't have that problem.
I've got used to the ride of them, and on the least hardest stifness there fine for day to day use. I just avoid roads I know are very bad/speed bumps when I can.