ALX 298:
20f/24r tipping the scales at 1680g/pair.
Ultegra hubs: 615g
Mavic CXP33 rims: 940g
DT Champion 1.8 spokes (64): 359g
Total weight: 1914g <-- 234g gain
Total weight with DT Comp 15/16 spokes: 1866g
Ultegra/DT 1.8
DT Swiss RR1.1 single: 830g
Total weight: 1804g
Total weight with DT Comp 15/16 spokes: 1756g <-- 76g gain.
For only a 76g weight gain, you can move up to a stronger, more forgiving wheel with 32 double butted spokes and not have to worry about checking your spoke tension after every ride as you do with a lower (sub 28) spoke count wheel. For 234g you can can go up to a wheel that would handle double detail as a minesweeper and probably stay trued.
I ride 32h Alex DA16 rims, 3 cross laced with DT Champion 2.0 spokes to Deore 535 hubs on my commuter/distance bike. I'm building a 32h DT Swiss RR1.1single, laced the same to a dynohub.
I've got 17 year old 32h Wolber Alpine rims, 3 cross laced with Champ 2.0 spokes to IRO high flange hubs on my fixed gear, and I've never had a problem with them.
In case you can't tell, I'm a big fan of DT spokes over Wheelsmith, and a recent convert to their rims over Mavic or Alex. Don't get me wrong; Mavic rims still kick some serious tail, but I like the DT rims on personal preference for picky reasons like wear indicators or a 0.4mm wider profile.