Hello, a couple of questions about MIUI

Jul 3, 2013
Hello MIUI friends,
I'm new to this forum and to MIUI, but from the thing I've heard- it is pretty awesome !
Long story short, since I don't know much about this modification of Android, I have these simple questions:
1. Is it possible to install a version of MIUI on my old LG P500? Will it run smoother, compared to android 2.2 Froyo?
2. Do phones like Samsung galaxy S(2;3;4), HTC, LG ect. get better scores in synthetic benchmarks with MIUI? Or the stock roms are better for performance? Because I have seen Xiaomi phones wiping the floor with some major brands, even when they have the same hardware.

Thank you !