They also tend to be available close in. I booked two last winter - both PHL-CDG round trips on different dates after needing to be in France on short notice for family reasons. I was able to snag one about 10 days out and one four days out, the latter being the only saver award available. I was surprised, but very glad ... using 60K miles for business class tickets that the web site wanted about $8K for close in is about the best use of miles on a cost per mile basis I think I've ever gotten.