I hear alot about O.S., Rex, Rossi, JP and the list goes on and on. I don't hear too much about the .21 size buggy engine from Collari. I know that they are primarily known for their on-road engines and the .30 size engine is for those who like to "bash" or just run for fun without size specs on engines. I have the Collari and it seems to be a great engine. I have never actuially seem a buggy operate as smoothly as with the Collari. I have had the V-Spec , Rossi and many other brands, and this one seems pretty good. It was in several buggies in rc magazines and it has been described as a "stump puller" and very smoothn in its acceleration. I like it alot. Does anyone else have one and what is your take FROM EXPERIENCE. If you have seen one run that can also help out alot...