ALL OK, a nice mix. Starting from the bottom, the Trek, the best bike and not a bike that you would "ought-grow" anytime soon. It's not a cheap bike. It has Sora which works well even though it's the least pricey of Shimano's serious groups, quite worthy. Few would critsize the Treks.
The first Performance bike appeals to me. Some may disagree but I believe it too is worthy. Without going into detail the parts are adequate and the frame should be well built too. GT's gotten a bad rap for a number of reasons, they're coming back and I for one respect their recent offerings. I've seen GTs, DiamondBacks & Mongooses out and about, ridden a couple as well. These were once more highly regarded and for rep. Places (not just hi-end stores) to sell them speaks to at least some level of quality. A member here just bought a different brand that also suffered some falling out of favor for one reason or another, perhaps no reason at all. He got a great bike, three years ago it would've cost him much more.
I just want to impress upon you that the bike is just fine. DO mind the sizes.
The Schwinn, another bike with "mixed" reviews 'till recently. A good choice but it's only available in a X large size. My intent is NOT to boss you into any particular size.
The GT small is for a man 5'7" - 5'9" ; XS for 5'5" or less ; XL for over 6'. (approx.)
Unfortunately (perhaps) they're out of the medium & LG. both very popular sizes.
DO take other opinions, charts, trying bikes-out , etc. into account, I'm only bringing this aspect to your attention as it's important. I'm 5'10", I can go small but prefer med., on some bikes large if I'm in the mood. You ought to ask a sales rep. or two.
The Schwinn is only avail. in XL. The sizing's similar to others.
Again, if the GT is avail. in your size, no shame in it. Nothing wrong in having the price differential for a car payment. Other choices are out there BTW