I FOUND A QUARTER! Came up heads, going Claws.
You quarter came up right. Go with Claws, as Dual Blades is pretty bad for Brutes relative to Scrappers. Claws effectively had its DPAs buffed when ported to Brutes, and performs much better even though they both use the same +damage mechanic that benefits Scrappers more (Blinding Feint, Follow Up).
Note that Dual Blades isn't actually that bad on Brutes - as long as you can avoid getting obsessed with combos early on. Waiting for combos is what kills DB for Brutes, from what I've found. Once you get some global recharge and enough powers for two of the combos (preferably ones that have a common power or two) and don't get too picky about which combo you're going for at any particular moment, it's fine.
Overall, the fact that it's pure lethal damage is of more concern, though a bit of research and choosing your enemy groups wisely will help with that.
In short: Don't wait for the combos, at least early on.
Claws and WP is a sleek build. Very fast paced.
Honestly, I don't care what I'm trying to do with the thing. Love the hell out of both sets of animations and I have idea's for either one, and no matter what I pick, it'll be /Willpower. So I'm just stuck with trying to decide between the two, and dammit I do not have a quarter next to me to flip.