I've flown with BCT Aviation (Kemble) & Old Sarum Flying Club, although I believe BCT is now under new managment since I was there.
BCT Aviation were very friendly people - can't fault them. They do have a substansially smaller fleet than OS (IIRC a couple of PA-28s, a 172 and a 150 compared with 7 PA-28s, a PA-28R, two Bulldogs, a Supercub, a Seneca, 1 152, and a 152 taildragger).
The two clubs do pretty much the same things, but OS can do tailwheel conversions, but this may or may not be of use to you (I'd certainly recommend it though!).
OS is also very friendly - I live about midway between the two airfields, and chose OS due to the variety of aircraft, good club atmosphere, and the 780m grass field (Kemble has acres of concrete runway, which is either a good or a bad thing IMHO depending on which way you look at it).
I'm currently doing my IMC/hourbuilding with OS, and would certainly recommend them to you - except if you live in Swindon you might find it much easier to travel to Kemble.
Also flew with Ultimate High at Kemble, but they do (very good!
) post-PPL stuff.