Giant Defy 2 would be the more relaxed geometry. I would suggest, if your dealer carries it, riding the Synapse. The rear triangle is much more compliant than the Trek 2.1 or 2.3 (same frame). Defy would be next. Trek last in back end comfort. The Alpha frame is nice, it just does not absorb road shock/vibration as well as the others.

Trek does the 2.1 in the H2 fit. Overall they offer three fits, but not all are available on every bike.

Can't speak to the KHS, Jamis...