Welcome to here! The Vader seems like a good bike as long as you are not intimidated by wrenching on it. They seem to be hit or miss out of the box if you look around at recent posts, but overall, once you get the bike consistent, it works out--for the price.
Without getting into Grom territory pricewise, but several hundred more $ than the Vader (I am thinking less initial work to get it started/keeping it running) is the SSR Razkull; however, that seems like more of a commitment over a few hour a week bike unless you have the extra few hundred dollars for piece of mind.
In the same category pricewise as the Razkull is the very similar bike from Ice Bear.
Here is one for reference
http://www.apscusa.com/New-Little-Mo...ded_p_767.html
Then again, here is the Vader at its low price (shipping not included, but still...)
http://www.powersportsmax.com/produc...ducts_id/20474
With Maxipad's videos/help here, you might be just as well off with the lower cost Vader. I have not read any post where one has failed catastrophically. I doubt you will be the first!