For the money they are ok - cheap and cheerful.
It's worth cheking the connectors have the right wires going to the right pins as they have been known to be "swapped" over on occasion. Also worth going over the wheel to check spoke tension as well as with most machine built wheel. Controllers are ok, hubs are cute or bafang so know brands with associated reliability.
pay by payapl to safegaurd your money and allow a long delivery time (I've been waiting two weeks so far for a battery) - six weeks seems to be the average and you'll be fine - just be prepared to be fobbed off if you recve a fault item 9doesn't seem to happen that often though) - if so - paypal dispute for your money back.