Hey, I just changed to the same cooler set up too. Mine is as such:
mini120: idle 30C, full load 58C (while playing FEAR), Ambient 24C, cooler fan setting low-low noise.
Medium fan setting, full load 50C. Noise-noticeable but mostly drowned by game play.
stock intel cooler: idle 45C, full load 62C (playing FEAR), AMBIENT 24C, cooler fan noisy.
I'm happy with the mini120 considering the price is 85 dollars. I get lower noise and cooler cpu than the intel stock cooler.
P4 670 3.8Ghz OCed to 4.18Ghz,
x1900xtx, x-fi fatal1ty sound card,
1GB PC6400 Corsair twin xms DDR2