I wonder way Xtracycle doesn't come out with another solid frame bike, something not as beefy as the Big Dummy, maybe on a lighter frma bike like a crusier or round tube mtn bike? No it will not carry the loads the BD does, and I'm sure some of us will still buy it because we don't haul book cases around daily just our kids and some groceries.
I always thought a Workman's bike built with a solid Xtracycle frame would be the ticket. But I'm sure other bikes would fit the bill as well.
Jerry