Here is a link going over the differences between Trane and American Standard from a large dealer in AZ who has sold both.
Nutshell, both are built on the same production line and identical except for color and logo. Even the price to the dealer is about the same... but dealers that buy more get lower prices. But there still can be reasons to choose one over another.
Trane vs American Standard, what is the difference? | Magic Touch Mechanical