Do a quick search, there are loads of posts about them - 99% positive, and there is also a discount for members, mine is booked in two weeks with another 6 from this forum, so can't be a bad thing.
I had my 1200ST done a few years ago. I ignored any after-treatment claims regarding increases in power and used my own arse-dyno to evaluate any improvements. They were considerable, and easily spotted! Highly recommended.