I used to work for them, although I wont say what I think of the company I have flown with people who have been elsewhere and wasn't impressed with there flying. Not speaking for myself, but the guys who teach there are top. As for Elstree I would stay far away from the place as possible. Grumpy controllers, Nightmare parking, 4 different circuit patterns (None of them a standard rectangular shape), queues for departure and expensive to land.
If you do decide to go to Cabair Fly at Denham or one of the others. If you learn at Elstree it will be more hassel than it's worth.
Good Luck