Never noticed but it's the same for me.
I replaced MIUI launcher by Zeam which is my favourite. It didn't make the phone faster overall as it usually does on other ROMS.
More importantly, the ROM gets real slow with Twilight, which I absolutely need for my eyes. Not sure if this multitasking related, or due to how the ROM handles the GPU. But that is disappointing I gotta admit.
Ok, since yesterday the ROM's been behaving badly. Like every second after launching any app, be that Gmail, Youtube, Dolphin Browser or whatever, android.process.media and download manager keep crashing. Obviously I have tried rebooting the phone multiple times and emptying cache, to no result. Not sure what's going on.