All the approved schools are good. BA are asking for bids from other schools to be tendered. Oxford has historically had criticism for treatment of self-sponsored students, and for crap admin. If you want details of SFT then email me, but I would recommend it, and it's a lot cheaper than OATS.
Jerez have recently sent a bunch of students home because they did not have the staff in groundschool to teach them. Wouldn't refund their money either. Not good business practice.