What are the disadvantages?
The good folks who offered guidance on my previous wheel building thread seemed hostile to them, without offering reason. And the only reasons Jobst (love that name almost as much as "Horst") recommended against them in his book are:
a) hub must be filed for the spokes to fit through, and
b) twistage aligns the flat spokes in a non-aero configuration.
Contrary to the advice of many, I just built up a set of Velocity Fusion 32-spoke, two-cross, with Dura Ace hubs and Sapim CX-Ray spokes.
a) The spokes fit snugly through the hubs with no filing needed.
b) Using this DT tool, I was able to tension & true with absolutely zero residual twist. Whenever I tuned up wheels with round/butted spokes before, I would always get a plinking when taking them for a test ride; zero plinking with these babies.
So are there any remaining disadvantages? As far as I can tell, the only ones are:
a) these CX-Ray spokes are overkill for a 32-spoke wheel because they're built stronger for aero-wheels with lower spoke count.
b) it's a PITA to carefully install and hold the above spoke holder before making even minor adjustments to the nipple. (I suspect this is the real reason seasoned wheelbuilders are hostile to bladed/oval spokes.)
I assumed that having twisted spokes was probably a bad thing. Not so?
It seems like most old time wheelbuilders disagreed or told me I was wrong at just about every choice I made when building these wheels, but the wheels seem quite sturdy, and 32 oval spokes are certainly going to be more aerodynamically efficient than 32 round (& twisted ) ones. Since I have access to an identical pair of these wheels with Ultegra hubs and round/butted spokes, I'll provide test results, using Garmin GPS and SRM power meter later this month.)