Redcat has the rotary too, ive pick one up from redcat with the rotary a while back. And ya the sh comes with blue heads always, but the vx's come in purple and blue.

A while back joey switched from the vx 16 to the sh 18, ya there is a difference between the 16 and the 18, but he said it was a HUGE improvement. Im not sure how much .02cc's will make, but like i said from the vx16 to the sh18 was huge.