One of the common questions people ask me about is race wheels, and whether they are worth it. I've always thought worth is a relative question, based as much on budget as performance. I remember asking Joe Friel why he always rode such nice wheels on his road bike, (Zipp 808's), for all his rides. He responded with, "Jim, by the time these wheels are worn out, they'll be obsolete anyway." Very true.
I came to ride the wheels I would race on, all the time. I was training on a 404/808 combination with a PowerTap, and on race day I would just add a disc cover I bought from Wheelbuilder.com.
A disc cover is simply two pieces of plastic which attach over the wheel securely, and make it a full disc wheel, in essence.
I had heard from John Cobb at a wind tunnel camp, (one of the aero gurus), that the disc cover was, "not as good as a disc wheel, but pretty darn close." Considering the investment difference, I was fine with pretty darn close.
Then I read this study, by Wheelbuilder.com themselves, and how the disc covers did compared to uncovered wheels, and solid discs. They even compared an 808 covered and an open-pro rim, with little to no dish.
Now, Wheelbuilder.com is in the wheel sales business, and the disc cover sales business, so one might argue their results are not independently verified, but one could argue by showing an open-pro with disc cover does better than an 808 with one, that they would likely be losing money if they sell open-pro's instead of 808's. (This doesn't take into account the rolling quality of the 808 vs open-pro, or bearings).
Perhaps it's time to put a disc cover on that wheel, and saving yourself some dough!