I've been riding my kits for 7 years. But pretty much all of the kits come from china - and most of that stuff pretty janky. Its cheap enough that I order 2 or 3 of everything (since getting one costs a fortune just for shipping). The wiring sometimes is backwards, the connectors are mostly junk, and somehow I've worn out a couple of throttles (how the heck is that???).

So yeah, there is a bit of futzing around. I'll say the stuff from EM3ev.com or ebikes.ca tends to be a cut above the traditional base Chinese stuff. Still, its tempting to get a fully integrated well designed well built bike. I just got an offer for some nice ebikes at 75% off, but my DIY stuff is still working.

you gotta be a handyman to keep a DIY bike running. I've learned a lot. ;-)