I’ve often found that the Business MileSAAvers to Europe can be less miles than the Economy AAnytime Awards, depending on the dates and availability (not all awards are one set "price" any longer.... e.g., for a couple weekends this July and August, One Way Economy AAnytimes from Europe are 110K miles each!).

I always prefer the Business MilesAAvers if I have a choice. You not only have the (much) better amenities on the plane (plenty of room, much better meals, lay flat seats, etc.), you have Priority Check-in, Security, Boarding & Luggage Service (bags are supposed to arrive first), as well as Lounge Access. We’ve also enjoyed fast-track immigration upon arrival at LHR. There are so many pluses to the Business tickets that make your travel dates much easier. If your dates change and the award availability is still there for another desired date, you can move your ticket at no charge (as long as the routing is the same).

I vote for the Business MileSAAvers, but whatever you choose, enjoy your trip!