Definitely go with the 207. The guys at Gougeon say that the 206 can cloud-up over time due to either improper mixing or incorrect ratios. I've done test panels with both and the 206 panel does seem to have a kind of haze. The 207 is nice and clear. It's also has a yellow tinge and gives you the jump on the nice warm honey color of spar varnish. I built both my boats with 207 and have no misgivings about the choice.