I dunno, tubulars are usually "tougher" (higher tpi - threads per inch), are WAY faster to change than a clincher (providing you prepared for everything), simply grab the tire and "rip" it off the rim, and put your new pre-glued tire on the rim, inflate and go. A little practice and you're off and rolling again in 5-7 minutes. Yanking a tube out of a clincher with some flimsy tire irons and then remounting everything usually takes me a good 20-30 minutes on the side of the road.

Rolling resistance? A good tubular should be able to run up to around 180-190psi, which makes the 120psi in a good clincher seem...well, flat.

The bad stuff? Not so much cost, although the cheapest clinchers are cheaper than the cheapest tubulars, the wheels are about the same price wise. The bad is that most bike shops will only stock one maybe two brands of tubulars (some don't stock any, some stock more) and multiple brands of clinchers. Need a new wheel in a hurry? You are probably out of luck, most bike shops will stock a 700c Shimano compatible clincher wheelset, good luck finding a tubular setup in stock. Gluing tires to the rims the first couple of times can be a messy treat.

And in the end, it probably doesn't make that much of a difference.

Andrew