Jekz - look - there is no "best" school for modular training in the UK.
Different people have different requirements! What is the "best car"? The "best laptop"? IT DEPENDS ON WHAT YOU NEED! Different schools offer different advantages.
Problem with the wannabes forum on PPruNe is, most people here, who consider themselves experts, have only seen a few schools first-hand and reckon where they did the training must be the best school, and you read crap like the training there was "second to none" and soforth. It's rubbish, because they have no way of actually comparing all the different schools in-depth and first-hand. Even if you've done modular training at three different schools, you can't make those statements with authority.
As a previous post said, get the list of approved FTOs from the CAA web site, then have a look at the individual schools and ring up the ones that appeal to you for more information. THEN, when you have a shortlist, you can consider asking about those on this forum.
Good luck,
KK