Originally Posted by
datako
Life expectancy of a properly looked after S-A gear hub is the life of the bike, whereas almost all the parts on a derailleur system are consumables (more so at the folding end of the market) and usually the cost of replacing the drivetrain means that the bike becomes disposable.
I hope this is true of S-A gear hubs. I know it is not true of Nexus 7 and 8 speed hubs. (FWIW, I do think that 3spd hubs are much more robust than 7 or 8 spd hubs with the same form factor).