I don't know anything about the Springfields, but I love my Assaults. The wheels they replaced were Campy Eurus, which were incredible and trouble-free for 10,000 miles. The Assaults are stiff and fast and Reynolds makes a solid product. Utah-based company with good customer service. The price is also right.

Given that, I'd get the 2010 404 all carbon clinchers. Zipp knows that the eff they're doing, but you pay for it.