Thanks for all the input. I will probably do to DFW - JFK - BRU route. I might as well maximize my miles as long as the company is paying. I'll be there working for two weeks with an additional week in Eindhoven, The Netherlands. I may depart out of AMS and route through LHR. I've never been on a BA flight.

As to the cost for all three routes, they are ranging from ~$890 to $920 so all routes are competitive.

Does anyone know if the train is first or second class when booked through AA?