Until a resident or person more familiar answers, here's a bit of preliminary information:
The Hyatt is inside the restored Union Station complex.
The Marriott, where I've stayed before, is much closer to the Mississippi River. In fact, if you were to exit the Hyatt and Union Station and walk east on Market Street (towards the River) you'd walk right to the door of the Marriott (which itself is across the street from Busch Stadium). From memory, I'd guesstimate the distance at about a mile.
The Embassy Suites is farther away than the Marriott, as it is located in the riverfront Laclede's Landing shopping and entertainment area. Not sure about the Renaissance, and I believe there's also a recently opened Westin somewhere in the DT area).
Hopefully a residents will respond and offer advice on whether the Metrolink light rail system might be useful in getting from the Hyatt to the other alternative hotels.
http://www.slfp.com/CityScapes.html
[This message has been edited by Non-NonRev (edited 09-26-2003).]