Subpar performance meaning there's plenty of better performing GBB's out there with more reasonable price tags once you factor in the stupid expensive mags.
I came across the AGM GBB M4 for the first time on eBay just a couple days ago. eHobbyAsia sells the gun for about
$195 with free shipping. They also sell the 50-rd mags for
$18. I think this is a very reasonable price.
I realize that quality is an issue and I have not had a chance to speak to someone who's played with both the AGM and the WA, but I think the AGM looks promising.