I've used both Brightsides and Interthane plus, like everyone says Brightsides is easier to apply but softer. I'm currently repainting the hull of my sailboat dark blue with interthane plus and am having a hell of a time! I tried the "roll and tip" method on the first 2 coats and no matter how I thinned (I spent at least an hour experimenting) I could not get the brush/tip marks to flow out. VERY frustrating. I have been follwing the directions to the letter & called tech support, they even admitted that the darker colors don't flow out well. I think on the final 3rd coat I'm gonna have to resort to spraying. be warned!