I have done DFW-FRA 4 times this year, twice in Nov. Without delays, it normally arrives 45min early.
I would advice against using AA code share on Thalys or DB trains, due to $$$. Its a lot cheaper to buy round trips after landing. And you only get AA miles on AA code share on those trains.
Other than Romer and Hauptwache in FRA, really not much that I liked. You can do in less than half a day. I suggest train to Koln, see old town, and Dom cathedral, thats another short day trip. Or better yet train into Heidelburg and spend the night. Walk Marketstrasse at night, and a must do is to walk to the middle of the main bridge to look at the castle at night. In other words, fly into FRA but go somewhere else.

Have fun.

[This message has been edited by pvcnco (edited Dec 20, 2003).]