I've had a bit of hesitation when pinning the throttle open at high-ish (6k+) engine speeds, changed the air filter + fuel filter and after a quick run up the road it appears to have got rid of it.
I just used a standard £12 filter from Wemoto, ordered Tuesday, arrived today.
Fingers crossed the filter will sort your problem out, this thread seems to be never ending. That said if you removed all the flirting from CRH and Ade it'd probably be about 2 pages