But my new MBP has been sluggish from day one. That is, from the moment I migrated my user files from my old box. It's possible that I got some stuff that affects performance. Three things helped:
* First, disabling the dynamic pager [1]. This one has a dramatic effect on performance. In theory, it will prevent OS X from swapping out apps unnecessarily (which it will do even when the apps are active and there is plenty of RAM). I did have some, but not much, swapping going on, but it still improved performance.
* Secondly, I uninstalled iStat Menus. I can't be sure that this contributed to the performance problems, but I won't risk reinstalling to find out. It seems to have helped a bit.
* Thirdly, I disabled Spotlight indexing of my home directory. This way Alfred will still autocomplete apps. Some apps lose their search functionality, but I never use Spotlight, and I find that I can live without it.
I tried the sandbox config fix, but it made no difference to me.
The remaining sluggishness seems to come from the graphics layer. For example, doing the Exposé "reveal all windows" command takes 3-4 seconds on my box and has a frame rate of approximately 1 fps. It's not great. I notice the reduced graphics performance when scrolling pages in Chrome, whereas Safari is smoother. I suspect this is Retina being a bit too ambitious compared to actual current graphics card performance.
As an aside, I believe OS X's I/O system has traditionally been its weak point, being a Mach-based hybrid-microkernel architecture. You can cause GUI scheduling problems by overloading the I/O system, and it's possible that this is exacerbated by having a SSD.