Maybe I've just got too much juice running through this thing. 4 HDDs, 2 SSDs, 1 Optical, GTX 680, Apricorn Velocity Solo, 14GB RAM.
BTW your config is not overwhelming for a 3,1 MP. Apple designed it to give a lot of grunt!
Nobody has asked yet -- what speed are your CPU cores? Mine are 2.8 GHZ. My understanding is the 3.2 GHz cores run notceably warmer.
Across the board you now have lower temps. If you have fast CPUs, then your system is likely operating well within what it's been designed to do.
Rather than using MFC to set a constant value (which wouldn't let the system ramp up the fan when it really needs to), I would first set it back to auto, run the machine with your usual loads, and see if the system seems to manage temps on its own.
If it does, relax and enjoy the ride.
If that doesn't work and you really want it to run cooler, then I would suggest setting MFC as
• PS, sensor based, Supply 1, min=44°C max=64°C
• Exhaust, sensor based, Supply 1, min=44°C max=64°C
See if you like that behavior. If the fans run high and loud too often, change the max temp +1°C to 65°C and see how it goes. Play around with increasing the Max (and Min) until you find where your machine runs cooler but not always loud (faint whirring is fine -- it's a constant loud swoosh you want to avoid except when the machine is truly doing heavy load. For example Handbrake might get you into swoosh-level, but playing a track in iTunes should not.)
On the other hand, if the min=44°C max=64°C settings seem comfortable, experiment with changing -1°C (e.g. Max=63°C). You might find it runs a little cooler while still staying quiet.
You don't need to be a tech pro to twiddle MFC. Just pay attention to what you do and the changes you perceive. If you don't like the results, it's easy to set everything back on auto.