MY .02.....
I have an 06 k9 with factory shocks (no air ride) and an 05 chopper that had air ride already installed when I bought it........I much prefer the ride of the k9.......
The biggest complaint I have with the air ride is that every time you start off, you have to pressurize the system (or bottom out pulling away when you forget) and every time you want to park, you have to depressurize the system so the bike wont tip over while on the kickstand. Yeah, the looky-loos at the bar will say "that's cool" but the routine gets old really fast without any real improvement to the bike's ride......YMMV