If you are *G with CO you only get 100% RDM bonus on Lh/UA/AC not LX Although I'm UA 1k, I would not go via IAD on a small regional jet. Also, my one transfer experience in yyz was really bad- to be hassled by security after 14 hr flight was not fun. Their security screening seems different than US. Their C seat is OK, but I prefer UA. Also, there's a nice LH lounge in JFK...