As with all these choises where ever you do your CPL theory and you pass then you will think that it is great!
Having said that, when I was looking there are only 3 places that actually do the CPL(A) theory - most places try to push the ATPL(A).
I chose GTS for the following reasons:
1. They let you pay in installments (3 modules)
2. They offer the most taught ground school (one week for each module)
3. They have very experienced instructors (20+ years flying each)
4. They were the only ones to send me a sample of the course material when I asked.
I have just sat my last 3 exams (10th and 11th May) at Gatwick - so fingers crossed. I am working full time, have family to support and have passed all the exams first time (so far - fingers crossed).
And of course I would recommend them - it is really great to be able to ask them any question and they can give you an answer immediately based on their flying experiences. E.g. Dave, an ex-RAF CFI / Jaguars / Lightnings / etc was explaining about gas turbine engine surge and recalled how a flame shot out of the front right intake of his Jaguar during a surge at 450kts!