Jamie Smart is excellent at marketing. His company, Salad Ltd, has put out lots of products and he has marketed them very well.
I haven't been on any of his courses, so can't review Jamie Smart's seminars, only his products.
Do I like them? Not really. Maybe it is because I am actually quite experienced in NLP, but I think that everything he has put out (alright, I have not seen all his stuff, just bought some of the "advanced" things) is basically for beginners. Since there are more beginners than experts, it's probably another proof that Jamie is great at marketing.
I guess I would say that he is okay. He knows his stuff and seems to be a good teacher and a caring guy. You could do much worse.
On a personal level, he is a very nice guy, as we had a few beers together at different conferences.
One thing I don't quite understand is his silly little feud with Eric Robbie about submodality eye accessing cues. There are several blogs out there where they are engaging in one-upmanship which is very annoying, as the three of us had several drinks together and it always seemed to me that they got along quite well.