How fast is Xfce's composite manager?

[Nikola Pizurica]

I just bought used GForce 2 MX400 and man it flies. On old dual Celeron  
(o/c from 333Mhz to 550Mhz :-)).
I love eye candy, but I found that with NVidia latest drivers, after  
short use of xorg's xcompmgr, I get hard locked.
So, is xfce's composite manager different then xorg's?
If yes, I will download and compile xfwm4 from source to check it out.

Nikola