I got myself a set of Mavic Reflex with DT Aerolites (32) on DT 240 hubs a few years ago. The initial idea was to get them as racing wheels as they are supposedly quite rigid, fairly light, not too expensive to replace in case of a crash and the tubs should give some extra safety in case of a puncture.
While I like the ride quality, the wheel is not really stiff and descending in a race situation north of 75km/h does feel quite sketchy. In fact I gave up using them and continued using my training wheels (Fulcrum 3) instead. For my weight ( 77 - 80kg) they feel much better particularly when descending.
So I still like the idea of an aluminum tubular rim but I would not get the above combination again.
Hmmm... can't say for sure, but I think it's the Aerolite spokes. They are very thin in the middle, but if the wheels are sketchy with 32 spokes, you have to wonder. I don't think it's the rim choice, Reflex's are a good tubular rim. I have several wheels built up with Aerolites and am not sure I'd use them again. I'm pushing 90kg. I have some Ambrosio Nemesis 32 hole rims I'm about to build up onto Campagnolo Record hubs. I'll be using good old DT Swiss Comps. Not the ligthest of wheels by any means, but classic and hopefully, bombproof.