Originally Posted by
chaadster
Correct, and specifically to your point, the SwissSide modeling that is (insofar as I can tell, although Flo did some good modeling, too) the source for these numbers being tossed around so imprecisely, does in one of their model scenarios nail the break-even slope at 3%, meaning anything steeper than that for a 70kg rider at 200w would be faster with 10% lower weight than a 10% reduction in aero drag.
In any case, it certainly seems like there’s very little need to parse use cases or choose sides, as wheels which are both reasonably light and decidely aero can be had new at pretty accessible pricepoints, like around $500 or so.
Obviously there are plenty of variables at play, but the above study is looking at an arbitrary percentage reduction in total bike weight vs total aero. The numbers I've seen from comparing actual wheelsets (Again I think it was from SwissSide) show a break-even slope much steeper than 3%. Probably because the aero gain for aero wheels is relatively high compared to their weight penalty.