Another possibility is that the 120mm fan is not getting enough "breathing room," is this mounted in a blowhole where it can get some flow going? If it's being choked by the bezel or something, see if you can cut the bottom of the bezel off so it can get some air.
I have two low-RPM 120mm Panaflos and have seen the YS Tech too. Mine are used as blowhole fans and put out plenty of air. My dual-P3 system is only 3F higher than room temperature inside, with one 120mm Panaflo, so I don't know how much more I could hope for... and that case has no other case fans at all. No complaints here.
Just keep it all in perspective, if your system is so close to the ragged edge that 1-2 degrees C. is utterly critical to it not crashing, then either back off a notch or slap that YS Tech in there and learn to like the noise!