A friend of mine has trained with him for over a year, he has brought her on to advanced dressage, she really rates him, afraid i don't have any personal experience.
I haven't trained with him myself but he holds clinics every couple of weeks at the yard I'm on. He teaches over two days & one of my friends always has a lesson on both days. She thinks he's fab. My best friend has had a few lessons with him too. She's found him very good & he's helped her lots. He always seems very friendly when he's around the yard.