"it wold receive some assisted air movement" I can't exactly answer your question but here is my quiet system: I use only one fan in the upper chamber of my P180 case. The top fan position is blocked off and air enters through the filter on the lower front and exits through the upper rear fan positi...

For the Q9450 Gigabyte says you will need BIOS revision F5 which was the first release.

You must connect the 4-pin power connector near the back panel I-O connectors.

Those memory modules are not on the Qualified Vendors List.

RE: MSI Product Uses Less Power

IC's come in a lot of specification combinations. Perhaps the chip that ASUS is using consumes more power for the same speed and costs 1 dollar less. Or, perhaps the MSI engineers were able to design better pcb interconnects and were able to run the NB at 0.1V less.

I use only one fan in the upper chamber of my P180 case. The upper chamber contains an ASUS P5WDG2 WS PRO, Pentium Dual Core E2220, 2 GB RAM, Wireless N-type Lan card, Satellite TV card, Sapphire HD 3850 and 2 WD RE 500 GB drives. The 1150rpm Scythe Gentle Typhoon does double duty by both getting th...

"I'll be moving it around considerably"

The Cooler Master Storm Scout has handles.

If the noise of any device in your system in above the background level noise (ambient noise level) you will hear it. The ambient noise in a quiet residential neighborhood is generally higher in the daytime than in the late evening. The challenge is to get the noises below ambient or as close to it ...

"isn't a heavier case better?"

Size and weight are a concern for people that put their system on the desk or table.

"Do bearings really matter this much?" Good bearings are quiet and bad bearings can make a lot of unpleasant noise. After lowering the blade noise then the bearing noise may show itself. "is there something I have missed?" I've never experienced any fans to have a perfectly linear relationship of rp...

"SPCR is about silent/quiet computing."

Yes, SPCR is about silent/quiet computing and some Gamers like their PC to be reasonably quiet and non-annoying at idle.

"One of the GPU fans was also spinning slower"

Perhaps the slower spinning fan and lower temperature of the lower GPU was due to the air flow path through the power supply.

"the rubber/foam type material"

With the side fan position and front fan positions equiped with filters and an optical drive mounted in the top position and the two drive slot covers filled with the rubber/foam type material a then all intake air will be filtered.

The 1150rpm Scythe Gentle Typhoon has the most non-annoying noise signature that I know of. I use one for cooling upper chamber of my P180 case. The upper chamber contains an ASUS P5WDG2 WS PRO, Pentium Dual Core E2220, 2 GB RAM, Wireless N-type Lan card, Satellite TV card, Sapphire HD 3850 and 2 WD...

The Scythe Big Shuriken could have the fan sucking the air from the pcb area.

I can't tell from the pictures what exactly your coolong limitations are but perhaps if I describe what I am doing with my system you can develope another way to solve your problem. The job of cooling a PC can be reduced down to getting the heat away from the CPU (and other major heat sources) and t...