Thudbuster on my Turbo Vado 3 and my other None electric bike. Gonna buy one for my Turbo Vado 5 SL. Works very well, dependable and not so very expensive.
Turbo Vado 5 SL here. I find it very smooth and quiet. About the same as my Turbo Vado 3, but the motor has a little bit of whine , dont bother me , I´m 60 years old and probably not as good hearing as some younger guy ;-).