I was looking at these myself and if WE has done a good job putting it together I might look into purchasing one myself. Hope someone has already taken the leap and can inform the rest of us about it.
I've spent minimal time handling it but its a decent 1st gen from WE. Leaps and bounds above any other 1st gen they have made, especially in the GBBR category.
That said, I won't be buying one until they make some refinements.
It can take VSR type buckings AFAIK but has problems sealing with the loading nozzle and keeping a consistent FPS even in semi auto.
I would hold off on the $400 until 2nd or 3rd gen rolls around, which should be in the coming months.
it is rumored the EBR should be revised a bit.