How much faster is a spinning wheel (of typical 500-year-old design, say) vs. a drop spindle, in the hands of someone with 20 years of spinning experience? And can the spinning wheel produce yarn that has similar quality?
From skimming around online, it seems that expert spinners get extremely fast with a drop spindle, and can produce higher quality yarn. But I can’t find a definitive answer about the comparative speed.
Drop spindles don't spin continuously, which gives the wheel an uptime advantage.
Even modern spinners who prefer a drop spindle often have a wheel on hand for plying. Spinning a thread out of a blob of fluff can be engaging and interesting, while plying is a tedious process that's hard to get wrong without falling asleep in the middle. There's not really an art or skill to plying. A wheel can knock out this boring part of the spinning process much more quickly.
From skimming around online, it seems that expert spinners get extremely fast with a drop spindle, and can produce higher quality yarn. But I can’t find a definitive answer about the comparative speed.