Welcome to the posting crowd. I'm not sure I qualify as knowledgeable but here are my comments on the bikes. They are all solid and similar bikes. I probably go with the one that feels best as far as seat and grips and stuff. I'd also ask the shop if they had any similar bikes at similar prices with 9-speed geartrains. These are all 8-speed. Not a big deal.

I don't like suspension seatposts so the trek fx 7.2 is out for me but the shop will probably swap that out if you ask. If that appeals

The spcialized has the fatter tires with the 7.3 having the skinniest tires.