In terms of driving smoothness (and stopping) and handling:
1: citaro (but I only drove the training bus before)
2: OC500
3: A22 euro 5
In terms of comfort, just switch number 2 and number 3.
The A22 is a nice bus to drive, but the moving off and the braking is just bad.
Citaro and OC may be a powerless bus, but it is enough power to get going.
Add on, the design of the citaro is just beautiful. Nothing come close it it