Technically, a 32 hole Velocity Aerohead should weigh less than a 28 hole. The rim should weigh the same before the holes are drilled, but by drilling holes, that reduces the mass in the rim and more holes means more mass removed. Though the difference should be minimal.

And as far as aero and depth, I saw somewhere once - can't find it now, sorry, - that the aero affect tends to plateau as you get deeper. Meaning the aero difference between 20 mm rim and 30 mm is much greater than between 30mm and 40mm.

Lastly, I've have owned four sets of Mavic wheels - Aksiums (temporary wheels picked up cheap that now serve as back-up/pit wheels), Elites (sold several years ago), SLs and CrossMax's - and have nothing bad to say about them. They are not necessarily the lightest, or most aero (Ksyriums suck in a crosswind), but they have been durable and easy to repair.