Bedford is good fun, but the GT circuit is huge. I felt that I hadn't fully learnt the circuit by the end of the day, although that was partly because it was soaking wet at the start of the day and then went through the greasy phase before drying out in the afternoon. So never really got into consistent conditions.
Plenty of run-off in most places, don't try taking the chicane between the two long straights at over 80 in the damp or it'll swap end easily enough
