I used to private hire and did some training with Hempels about 10 - 15 years ago. The fact that they still have some of the same staff (eg CFI) says something to me. There is LOTS of experience there in all its forms. Barry can come across a bit gruff at times, but on the other hand it takes a special kind of pilot to jump out of a Tiger Moth and into a Mig15, then a Harvard and then a Yak 52.
I did my first few twin endorsements there and a tailwheel endo too. Very thorough.
I have no experience with FTA.