Last week I got my old derailleur lightweight out of storage for a commute to work and back. This is 58 kms - most days I use a Brompton folder and trains.
The derailleur bike was a wee bit faster than my Raven Tour, but the weather forecast of no rain was wrong, so any time I gained while cycling will be more than offset by the time required to clean the derailleurs, chain, sprockets, etc.