We have one day to spend in Luxemburg City and we were thinking of spliting the day into half there and half in Trier. Is this a good idea or should we spend a day in only one place.Thanks!

Half a day isn't much in either place, especially if you have to figure in travel time. I've been to both. Luxemburg is nice but Trier though smaller has some magnificient Roman ruins including the Porta Nigra and Charlamange's basilica, which for me evokes Rome in a magnificent fashion. It also has some great Reisling, which on it's own is worth the visit. You'll love it.

It makes sense to me. Luxembourg isn't all that thrilling unless you also visit the Luxembourg American Cemetery where many of the American troops killed at the Battle of the Bulge were killed.

Trier is worthy of a full day: The Catholic and the Protestant cathedrals, Roman Baths, Roman Antiquities Museum, Karl Marx's house and the Porta Nigra (Roman town gate). There are also quite a few wine tasting opportunities nearby as well as excellent restaurants.

Another possibility is to just spend your day exploring Luxemburg itself. You can get a nice overview in a day and there are some lovely towns. Echternach and Vianden come to mind. At the latter, the castle on the hilltop is a spectacular sight (from the outside - nothing much inside).

Well it sounds like I have one of those good problems, all choices can be the right one. Thanks for the input. I am leaving on the 28th and will post where we decided to go when I return. Thanks again!