Not to dog this issue to death, but here is my experience with 28 hole wheels: I built my first set of ultralight racing wheels about 1980 with 28 hole high flange Campy and Ambrosio Crono rims (I came to call them ambrusio groano!). I had problems with the spokes pulling out of the rims (too hard I think) so switched some time later to Mavic GEL280. These have held up fine. I should mention my fighting weight is 145. On the clincher end of it, ALL my road wheels are 28 spoke. I like the Wolber Profil TX (no longer available) as they were just bombproof. Since then I have liked the Campy Moskva (lighter but still very strong, and now also NLA). I think any similar high-quality aero-shaped rim will work in 28 spoke for most riders that are not too heavy. Of particular note, I built a set of tandem wheels in 1990 that are still in fine shape, with 28 hole front and 32 hole rear, with Profil TX on Dura Ace hubs. These have seen many miles (albeit on an unloaded racing tandem) and have rarely needed truing. So when I built up my titanium racing tandem last year I went a similar route, and built up Velocity Deep V on XTR hubs, 28 front and 32 rear. Of major importance is using the appropriate spokes for the job. For many years I have only used spokes that take 14G nipples, but I use 14 straight, 14/15, or 14/17 or a combo of depending on the rim, rider weight, and what side of the rear. I use one gauge lighter on the left for all rear hubs except something totally symmetrical. Helps to balance spoke tension right to left.
Bob Freeman