I used to repair them. They are pretty good. In Canada they are usually built to go faster than is legal so they have a speed governor you can detach. Not recommended, of course.

I recommend utility over looks. Lots of the cool looking ones break down compared to the large, lame ones (emmo GT80 comes to mind). Find ones with standard batteries as some will use wacky 16v ones that are harder to find stock and are more expensive.

Lithium is great but was more expensive than the stock sla. A few garages were burnt down from poorly made packs...