I have never used anything from them. I have heard some good things about several of their products, and some not so good things. Their Oxyblaster seems to be very popular for T/G. A lot of Oxyblaster fans here.
You will always find a lot of different opinions (especially here), but ultimately, it's about how the products work for you. I think they are a reputable enough company to warrant testing them yourself under your own conditions.
Personally, their website gives me just as big of a migraine as their print catalog.