Same heat, different speeds??

[serialtoon]

I just bought a Tuniq Tower 120 for my Pentium D 805. I decided to try out some different overclocks and log the temps. I started at stock speeds. 2.66Ghz and logged 48C idle and 58C loaded using Orthos on small FFT's. I then moved up the latter to 3.0Ghz. Same idle and same load. After that i went to 3.2Ghz...same idle same load. I thought, what the heck...and went to 3.6Ghz. Heres where it gets interesting. It idles the same, but the highest it reaches in terms of heat is about 65C. Im fully stable and not crashing what so ever. Im just curious...is this what you guys would call "good cooling"? I mean i just dumped 70$ on the Tuniq. Should i be at a better cooling? Should i try to reseat the cooler with a better thermal spread?