I did one a while back for ratterrier, hes been happy with it. I have been going to do another and do some testing to see of it hurts top end. For a low and mid tuned machine I think there good. Just don't have the ree tip area to flowat higher rpms.

I'm pretty 'HAPPY HAPPY HAPPY' with it. I dont have a V Force cage to compare it to. I went from stock porting, pro circuit pipe, 39PWK and a stock Rad Valve to Barlett Porting, Shearer Pipe, 39PWK and a ported rad Valve and she rips now!! Before it was a GREAT trail quad with all the low n mid I had but I got my tail kicked on the drag strip by everyone....even a couple over weight 440ex thumpers.....the sand dunes call for a screamin setup on a 250 and thats what I have now and I love it!! My buddies with the 400s, 440s and piped 450s.....they dont like it so much tho.  =)