if u ask me how good is 4 stick
u asking the right person.

i hv tested on 4 stick running:
corsair black 3200 rev1.4 3338 tccd
corsair pro 3200 rev1.2 3338 tccx
gskill fc 4400 2.5448

and the feedback is, sandramark quite bad.
something that need quick responce from ram, when the l2 cache is fully in use, u feel it different from 1T and 2T.
and 4 stick is only 2T when going high freq.
this not matter with any board.
4 stick, >200mhz, 2T for sure.

but still, 4 stick giv u more benefit.
ram banyak, boleh buat ramdisk.
can play bf2 smoothly.
can run many different program

it is quite hard to reach ddr600 for 4 stick.
try for ur luck.
i never reach tat top.
even the lastime opteron 146 never give me that taste.