simon, guess you will not like hearing this, but the top two strokes, (ex-works aprilia AF1 250, Honda RS250, TZ250 4DP) were doing 2:12-2:13, there were also some british icgp guys with 350 Yams but they were slower....
The top endurance big bores were lapping 2:06 - 2:08.
Situation might be different in other circuits of course
Good series indeed, if you can afford it. Some of the teams have WSBK sized trailers/workshops parked outside the boxes and that Suzuki UK Katana had brand new RG500 replica forks CNC'd out of a solid magnesium chunk.... that piece alone must cost like my entire motorcycle collection!