I have mixed feelings on the Av-Matoran build. Aesthetically, I find it works, though the wider torso is perhaps a bit misshapen. Mechanically, it does run into troubles, in that it's not readily compatible with any other constraction-build. The torsos are overly complex and the limbs use both balls and ball-cups. I think it can be used for MOCing, but it doesn't offer much of an incentive to do so. It's arguably the most interesting in an historic sense. On one end, it's the spiritual successor to, of all things, the McToran build. You can snap it together in a minute, but good luck MOCing with the torso and arms. On the other end, it's the second leg in LEGO's journey towards a simpler, more set-efficient, and more cost-effective building system, and the first attempt at adjusting the constraction system to this end. It's the feathered dinosaur to CCBS' bird. The monopiece torsos, the bi-connector limbs, the lack of Technic pins (save as weapon and mask connectors,) the ease of building, all these things have their origin in the Av-Matoran. Had it not been for the Extinction Event of 2010, we would probably have seen a more gradual transition towards a CCBS-like system. As Telluris demonstrates, cross-pollination between the Av-Matoran and Inika-builds was something the designers were open to, and I imagine that, by 2011, we'd have seen a number of parts designed for both. Speaking of which, I do hope that, one of these days, we get a detailed look at the original plans for post-2009 BIONICLE.