The alpha is kind of a different beast. I know there are more 'regular' models but I bet any one of those are close or heavier than the G4.
And the polaris sleds still bend a arms easier, have shocks that go to shlt faster, tracks that fall apart sooner and tunnels that bend easier. Still props on building them so light. They'll be light until you need to replace something. Somebody needs to push the envelope after all.
Speaking of envelopes, how about those Doo bulkheads??