Campag Zonda's and Fulcrum Quattro LG's. . . . able to compare fairly
The Zonda's were Quicker off the mark and when accelerating, and faster on the climbs, but could not retain the same top end speed as the Quattro's do. They are also a lot stiffer, so feel the umps, but corner like on rails.
Reviews online (pasted/edited below) - summary: The Zondas are lighter - they "punch into acceleration and maintain momentum on steep climbs"

. The Quattros are heavier so once up to speed will 'roll well' (angular momentum? aka 'achieve greater top end speed'). What would be interesting would be
@bpsmith riding out with a power meter and doing some hill climb comparisons (keeping his power the same) and also getting on a decent flat road and, ideally the same evening/on the same ride, doing a few 5km keeping power metric the same on each wheelset, and see if the Quattros are faster. The issue of how wheels 'feel' is analagous to the idea that riding on 23s is faster because you get a 'firmer' ride: and a firmer ride is a faster ride, no?
Campagnolo Zondas
http://www.bikeradar.com/road/gear/...ets/product/review-campagnolo-zonda-14-48295/
Campagnolo’s light (under 1600g) and super-tight Zondas are great if you rate speed over comfort. Though not toeing the ‘fatter is better’ line, the rim isn’t super-thin so won’t unduly pinch fatter
tyres. The front rim is slightly shallower than the rear, for more responsive, windproof steering. The Mega G3 lacing clumps the bladed spokes together in two driveside/single offside batches, and it’s not just cosmetic –
the rear wheel is seriously stiff with great power transfer. The Zondas put
punch into acceleration and maintain momentum on steep climbs, though the ride is on the firm side. The bearings are smooth and the bombproof steel freehub is available in Campag and
Shimano/
SRAM formats.
Fulcrum's new Racing Quattro wheels
The Quattros most noticeable feature is the 35mm deep aero aluminium rim which with the oversized flange on the rear driveside hub keeps the spokes short - resulting in a strong wheelset. Their 1,787g weight (a little higher than the claimed 1,710g) isn't particularly light weight . . The rim is stiffer radially than a traditional shallow box section rim which means less spokes can be used to build them up. There's 16 stainless straight pull steel bladed spokes up front and 21 in the rear wheel. They're held in place at the rims with smart red nipples [NB aluminium] and laced radially at the front and use the company's '2:1 Two-to-One' lacing pattern in the rear wheel. With two spokes on the drive side for every one spoke on the non-drive side, the tension in the spokes can be higher and evenly distributed.
One downside of all that radial stiffness is that on some of the rough roads of my test circuit they made for an occasionally harsh ride. They're fine on anything smooth but along a road where the top layer of Tarmac is breaking away, they can be a touch jarring. They're impressively strong though... I've battered a few potholes on night time training rides and they show no signs of dents or dings, nor have they deviated from true. Slinging the bike around reveals that
while acceleration is limited due to their weight, that once up to speed they roll along with good pace. They're nicely responsive when weaving the bike through fast corners and feel solid under heavy sprinting and sudden change of directions don't faze them either. So, a very tough and strong wheelset with reasonable aero speed, they look good with smart decals and they're very durable with the bearings still running smooth. For the money, we're prepared to overlook the occasionally harsh ride and enjoy their fast ride performance.