Just built a set for myself
They built up straight and true no problem. In the past I've always felt Mavics built up nicer but I must say these were the best Sun rims I've built, easily on a par with Mavics.
I've only got about 6 rides of 10 to 15 plus miles, but they're on my rigid front end, softail (about an inch) rear Dekerf, and I weigh 210 on a light day(okay, 215), and I'm running 2.0's or the occasional 1.9. Most of the rides have been rocky singletrack, where I'd normally ride my fs, but with the (relatively) new wheels and new fork, I've been riding this bike.
After checking the wheels the other day they're still straight and true. And they were decently (significantly

) cheaper than the Mavics, and claimed lighter. I never weighed them, but my wallet thanked me!
I will say that despite my current girth, I've always been easy on my wheels.
Get the Suns, I don't think you'll be dissapointed.