A couple of comments:

That 620 is huge! The others are relatively consistent in size - 54-55 cm. Size does matter here. You'll want to be sure you get something that fits reasonably well.

The Schwinn, the Raleigh and the 460 are designed for racing and/or sport riding. If that's what you are looking for, they all seem decent choices. My personal preference is for steel - for durability and IMO a sweeter ride - which would put me in agreement with you at having the Trek 460 at the top of the list.

If you're looking for something a bit more comfortable for longer rides, or to carry a bit of gear, my advice would be to take the 728. That is one beautiful ride!