The wheels are heavier than a normal clincher and the tires are heavier due to the bead that must be placed in them to keep the tire from blowing of the rim. They are only 127 tpi and weigh a claimed 290 grams. Vittoria Open Corsa CX tires are 290 tpi and the new Conti GP4000S is 330 tpi.
A Conti GP4000S weighs 205 grams and a latex tube weighs @ 50 grams. 255 is still lighter than 290. And that's rotational weight!

Lets' examine:
White Industries H1 hubs (32 hole)
Sapim CX-Ray spokes
IRD Cadence hoops
Alloy Nips ============== 1400 grams (observed)
2x Conti GP4000S w/latex tubes=== 510 grams (observed)
Total== 1910 grams

Dura-Ace 7801-SL 1560 grams (claimed)
2x Hutchinson Fusion2 tires 580 grams (claimed)
valve stems 20 grams (claimed)
Total== 2160 grams

250 grams difference = more than half a pound !!!

The rolling resistance theory is still up in the air...likely in your head...

I'm not a luddite by any stretch, but you simply cannot tell me that a heavy, 127tpi tire rides better than a 330tpi tire with a latex tube. The ride quality you're feeling is due to the fact that you have 90 pounds of pressure in the tire versus 120-130 with a regular clincher and the fact that the wheels just aren't all that stiff (yes, I've ridden them!). And if you cut the tire on a ride, you're just as screwed. Flats will require either using that stupid goo sealant or, you guessed it, putting a tube in it.
The wheels also aren't readily serviceable. There aren't going to be many shops that keep funky spokes laying around...