I'd contest this remark. Placebos and all that, fine. But if you get a nice light wheelset (say sub-1400g, and if you're fortunate to have some, sub-1100g, and both of them tubulars) and a "regular" wheelset (1800?g), it's going to be hard to say that both wheels spin up at about the same effort.

In fact, if you get a chance to try two sets of wheels, you'll be astounded at how fast your bike accelerates. You literally need to adjust your riding style to accommodate the much shorter acceleration time.

Fine, it's 1 or 2 lbs but that's what it is between my tubulars and some of the clinchers I have - and it's all in the rim/tire area since the hubs are identical and the spokes are close if not the same (technically the clincher spokes are longer because of the non-structural fairing, but I doubt I'd be able to tell the difference between the spoke weights... and the spoke counts are same/similar).

Spin up, btw, is much different than weight overall. Light wheels don't help me climb better. I still go really slow once I get into my FTP mode (i.e. blown up). The difference with lighter wheels is that I can accelerate harder, especially when I'm more fresh.

Wheels don't make the difference between riding "levels", but between riders of the same level, wheels can make a significant delta in performance (acceleration and rolling/top speed). So giving an aero wheelset to a 23.5 mph time trialer is not going to make them a 28 mph time trialer. I know because I'm that 23.5 mph time trialer. If you give normal wheels to a 29 mph time trialer, that person still beats the 23.5 time trialer.

I've won sprints on aero tubulars (light + aero), box section wheels (usually light), but never on heavy aero wheels.

cdr