Personally, I think the "32 spokes for a clydesdale" theory is a bit too conservative. My primary wheel set has 20 in front, 24 in back and they've been just fine after 2000 miles with just a break-in tune up at 500 miles. Newer, "aero" deep V cross section rims are stiffer than the old box section rims like the Open Pro and can work with less spokes, so long as the rim ferrules, hubs and spoke nipples are built for the increased load.