Go a step even further

Based on the below, the fan in the PSU is a Sanyo San Ace 36 Series and if I am not mistaken as I can barely make it out the 750mA which produces 58.5dBA.
There is a lowered powered, lesser CFM and quieter fan in the same series at 52dBA
All for a whopping $18.00!
Even looks like the screws on the PSU holding the fan in place meaning it should be a cinch to swap out.
Obviously the big question is, lower CFM how will it affect the PSU?? Maybe Spondoolies can test that. If they green light it everyone simply get one swap it out and be done.
The two PSU fans in question:
http://canada.newark.com/axial-diagonal-fans/series/san-ace-36/pg/810091845 http://mineforeman.com/wp-content/uploads/2014/03/SPTechPS.jpg