We've kept it fairly local to us so far for my son (Honda Cadet) and only visited Clay Pigeon, Mansell, and Llandow. We tend to look around at where is available when we want to go, as some will be hosting race weekends so unavailable for open practice. We do intend to try Forest Edge shortly too. As for the tracks themselves, our first outing was clay.
Track is fairly small and getting a touch tired in places but for friendliness, staff, help and marshalling, I genuinely can't fault it.
Shop is well equipped and they can't help you enough if you need spares.
Mansell is a fantastic track with a perfect surface and the facilities are excellent. Everything is booked online though and you don't get the family orientated feel. It's also expensive if you aren't a member, and is only open for practice once per month due to noise restrictions (daft considering its next to an airfield!) so it does get quite busy, which also means you don't always get a huge amount of track time over the day for each class.
Llandow is another extremely friendly place. Again like Clay, it's getting a bit tired in places but is a really good layout and is a good length with challenging corners. It has the family vibe and a well stocked shop as well, and I've also heard really good things about the restaurant on site.
I'll report my findings on Forest edge during the mid month practice (March).