In my previous job, based in Brussels, the company sent me all over the world, and quite frequently across the pond.
The instructions I left with our travel agencies were really quite simple: No US carriers and no London Heathrow, apart from that don't really care.
I didn't, and still don't, care for the miles. When you spend upwards of 150 days on the road, about the last thing I wanted to see on my days off was another bloody airport/aircraft/hotel combo. Many of the airlines I flew did not have first class, so one couldn't even blow the miles upgrading from J to F.
On almost all my travels East I've used Emirates, and the product they deliver is miles ahead of most European based carriers. The distance US carriers is behind EK should be measured in furlongs, lots and lots of them.
And I haven't even mentioned the cabin crew on EK vs, say, DL on a long-haul flight. Suffice to say that, on EK you won't have to wonder where the lead hostie has parked her zimmer frame.