I used Epoxy from US composites on my petrel build a couple of years ago. I used it because it was cheap (about half the cost of MAS) and I didn't know better. My glass job turned out pretty good (for a first timer) but after just a couple of months, whitish spots began to appear randomly on the boat. The epoxy seems sound, it just isn't clear. I might be wrong about their product, and I apologize if I am, but I think you get what you pay for.
Rick