I've heard mixed reports about rubber surfaces. When we did ours, we automatically assumed rubber would be best. However, we were advised by several companies that we could have it if we wanted, but for a very similar price we could have a mix of silica sand and fibre, which is what we went with in the end. Have to say, it is fabulous and does not cause us any problems (the rabbits also love it and spend endless evenings digging it up only to be chased off by myself and OH!lol). I guess also a school is only as good as the drains you have put in.....But, that isn't to say the rubber is no good - but I do know, that it makes your horses legs black and dirty! And, you can get bits stuck down exercise boots if you use them. Mind you, having said that, the fibre surface could probs do the same (I don't bother with exercise boots on madam).
We used Equestrian Surfaces - they are based in the North of England and are very good.