How many other players were being tracked while you were playing Jane's or Wings of Prey? I don't remember the Massive Multi-Player versions.
How much additional terrain was being mapped while you were flying alone?
That may be the difference between here and there.
wrongway
I don't understand how simple
2D clouds are going to kill someone's framerate. Does looking at the ground kill your framerate? No. If 2D clouds were added, they would probably cause less of a FPS drop by looking at them than at looking at the ground.
The game only renders what you are looking at, not the entire map/world at the same time. Currently, if you look at water, or a empty area in the sky, your FPS will always be higher than when looking at the ground, which is more detailed. Are you saying that there are people out there who can only play this game when looking at water or empty air? If your computer is SO slow that it can't even handle the ground textures, then it's either a $200 piece of crud from eMachines or something, or a 10 year old laptop.
SIMPLE 2D clouds, are not going to affect your FPS in anyway.