I love Velocity rims. I don't have experience with the Chukka, though. I have the 36h Dyad rim on my rear, built up around a Deore LX hub. My weight is much closer to 300 than it is to 200, and the wheel has held up (no broken spokes or hub issues) w/ only one $25 truing/retensioning along the way. I't been a daily (decently loaded) commuter and weekend ride bike and I've got close to 3,000 miles on the wheel at this point. I had hoped to do an overnight touring trip or two in August, but circumstances didn't allow it. Nonetheless, I'll have no qualms taking my Dyad rim on tour when I finally get to.

So, I hope I'm not muddying the water for you here, but just wanted to give a vote from personal experience for the Dyad...