Nope. Check the specs of high-end wheelsets such as Hyperions, Boras, Easton 90's etc. The tubular versions are always considerably lighter - on the rim, where it really matters.

Does have anyone have evidence that pro road riders are competing on clinchers? For sponsorship reasons they may say that they are, and they do 'modify' the labels on tubular tires in order to conform with sponsorships, but why would they actually ride clinchers? Clinchers are heavy, suscepable to pinch flats and tube blowouts, and when you do have a sudden flat, you have to survive navigating on the 2 metal rails of death. On tubulars, flats are a lot less frightening prospect.

So I bought a vintage set of tubular wheels on the weekend at a yard sale. Campy Record hubs with Omega rims c/w good tires. $100 for the works, including a minty 7-speed cassette. I have way too many wheelsets of all types, but I only bought them because I have never seen a 7-speed Campy cassette hub. I had a lovely ride in and around Capitol Hill on these this AM.

Right off, these wheels have lower rotational inertia than any clincher wheelset I have ever owned. In fact, every vintage tubular wheelset I have is lighter than every clincher wheelset I have ever owned. It is that much of an inherent advantage.