Haven't seen anything but I would guess they will be comparable especially since the atrix can't clock it's cored at different speeds I believe the orion can do that .but we won't know until later this year when they can compare them both
The new superamoled plus on the S2 is said to be more efficient than the original, which is more efficient than LCD. The Atrix has a bigger battery. My experience is that the screen is the ultimate killer of battery life, second only to the wireless radios. I don't think the CPU has that much of an impact on battery life, especially if you are just doing boring non-gaming stuff. I really have no idea though so I'm just talking smack to waste time until a release date is confirmed.