The Jetmoto would have the better quality, and have an extensive parts and aftermarket supply. They are pretty easy to get hold of at the headquarters, too.

Vbike will be slightly lower quality, but if you aren't going hard on the bike, it should do ok. Vbike is a good company to deal with--I think Tim is the main guy or owner, and he is a straight forward character.

If you want a stronger bike, and are willing to pay a little more, then the Jetmoto is the one to get. If you are starting out, and not planning on all-out racing (you wouldn't want to do that with the Jetmoto, either), the Vbike should be allright.