i have a 2017 that i retrofitted (upgraded!) with the factory handlebar switch from a 2018. i’ll admit that the walk assist can be finicky, and it’s hard to keep your thumb on it sometimes. i have had to turn the bike on and off before to re-activate it. but, it is a godsend! i use it every ride to help get that heavy bugga up two flights of stairs! wheelspin? um yeah, i also find reduced braking traction in the rear… when there’s no rider on the bike!