Always preffered the losi xxx series of cars to the B4... Ive ran an X-6, B4 and a XXX-CR and went back to the XXX-CR...
Only thing i can say is borrow one and have a go or pick one up second hand..
I ran mine in at the southport regional this weekend (fast atsro track with some cobbles, tarmac and concrete, the car was awesome!!
I qualified 14th out of about 66? which i was made up with, dont think i would of got that high up with a B4, and possibly not with an X-6...
Its swings and round abouts though, people that run them will say they're really good, people who run B4's will say stick with that...
Im getting a cougar soon, but ill definately be keeping my CR as back up
Dont know where your based but if your in the UK, near southport your more than welcome to try mine