Just a personal opinion, but I thought Paris was a real pain in the ass. Stroudsburg is nice and it is a short train trip from Luxemborg. Of course if you do Paris, you could ride the TGV 200 mph trains. Thats kind of fun. If you have the time, consider a train trip to switzerland. The scenery is outstanding. There is a "chocolate" train that runs from Montreux. Visits a cheese factory and a chocolate factory. See
www.seat61.com for good train info.
I am leaving the Czech Republic today. We are doing a cruise from Barcelona that will touch some of France. Have a good trip.