No actual experience as of yet, i'm off to Aerofan next week to do the instrument rating.
However one observation I have from the posts above is that, it depends if you are wanting to go modular or Intergrated....
If you are going intergrated I would suggest FTE Jerez or Adventia in Salamanca although I hear they are fairly booked up.
Your modular options are Aerodynamics (Malaga), very popular but personally I dont think malaga is the greatest place to live.
In Madrid you have: American Flyers (owned by gestair), Aerofan, Aero Madrid, Aeromed, (by the sounds of it not the best option), topfly (barcelona), and a few more.
As you dont speak Spanish I can suggest Aerofan as they have a very nice English chap, who deals with international bookings and they seem to be setup well to cater for English students. However if you do choose them I suggest arranging your own accomodation. (
www.idealista.com)