I agree on the 28PWK's, don't know anyone yet, other than all out drag racers that don't like them. In my opinion the Mikunis are harder to tune.
Here is the hot tip on the PWK's, the 2001 Kawasaki KX100 came with a 28PWK on it, the list price for the complete carb is around $90 each. The only downside is the right carb needs to have the idle screw moved, or you just deal with it on the inside.