When I ran Leopard I had no pinwheels, expose was smooth and the swap file was hardly used. In Snow-Leopard I get regular pinwheels due to strangely high swap file use even when RAM is available. Expose and Spaces judder rather than change smoothly. (others have mentioned these problems too). I felt that Snow Leopard was a change of the underlying coding (64bit, openCL etc) and that the memory and interface issues were ignored/overlooked. Do you think apple will address these things with Lion?