I don't ride on the track, but my Monster 900 is a blast on the street!
I don't think I'd buy a 620, though. The 900 is the same physical size, is easy to handle (pretty light), and you'll grow into the extra power.
The thing that makes the 900 soooooo much fun is the TORQUE. Twist the throttle at any rpm and just feel the torque.
Definately the best street bike I've ever owned. In my younger days I had a lot of zingy inline 4 sport bikes, but this is more fun to me.
I think reliability is very good these days, at least in my experience and from what I've seen in general on the Monster boards. Compared to the complexity of a car, a Monster is a fairly straightforward machine.
