My Cross Check is the smoothest bike I've ridden - smoother even then my suspended mountain bike and hybrid. It's the bike to use when my bag is heavy, or I just feel the need for a gentle ride. I assume this is due to the longer chain stays, fork rake, and relatively relaxed geometry. It's well behaved and versatile, but I can still get down on the drops when fighting a head wind.

You're thinking too much. Performance and comfort depend as much on fabrication technique and parts selection as on frame material and geometry details. Do some research, then do some test rides.