Hi. For your type of riding (light recreational), I think all of these bikes will fit your need well. The primary difference between the two Fairfax model is hydraulic disc brakes vs. mechanical and 3x8 drivetrain vs. 3x7. 3x7 drivetrains often incorporate a cheaper freewheel hub design, but that's not the case here -- Marin actually uses a 7-speed cassette on the back (that's nice). For basic riding, either bike will do well.
The Jamis is unlike any of your other choices in that is uses a chrome-moly steel frame and fork, whereas the others use aluminum alloy for both. It will probably feel the most compliant of all of them (since steel typically soaks up vibrations better than aluminum). There really isn't a weight penalty -- the Jamis is 27 pounds, which is commensurate with the others. The penalty is cost -- the Jamis is about the same cost as the others, but comes with rim brakes vs. discs. It would be nice to have rim brakes at this price point with the steel frame, but we can't have it all, right?
I suggesting riding all three brands to see what feels the best to you.