My 60GB is whisper quiet. It makes about 1/4 of the noise of my PC idling, and is barely audiable at 6' away, even if it has been on all day playing/folding/playing discs etc. Without exaggeration, it is about half as noisy as my friends 360. A noisy one could be due to poor ventilation arounf the sysyem, causing it to suck hot 'exhaust' back in, or very unlikely, a bad cooling fan.
I have a couple of usb powered cooling fansm which I use occasionally when i have my PS3 in my slightly smaller than ideal AV unit. I use them to disperse the hot air from the side and back.
On a similar not, I have hear that the cooling is much more efficient in the vertical position, so if that's an option...
As far as the G25 wheel compaerd to the EX, the difference is rather large. The majority of the G25 is stainless steel, whre the EX is very plasticky. One review I read even called the EX still a 'toy' compared the G25. I would probably agree.
Theses are the advantages of the G25 I can think of;
- Dual motors for better feedback and ressitance
- Much better construction and meterials
- Pedals are properly weighted with gas cylinders behind them. Plastic, cleaper pedals have no resistance, especially on the brake, which makes accurate braking impossible
- 6 speed box

- Leather wrapped wheel for comfort and realism.
The only downsides are that you can still feel and hear the gears in the wheel, which is still much better than most other wheels, is still noticable.
The 6 speed gear shifter feels slightly less well built than the wheel or pedals, and is a little light. It is usable, but not quite the same quality as the rest of it.
As far as noisy pedals, i'm not sure exactly what you mean. Coming off the pedals quickly does make the pedal hit back to resting position with a bit of a clunk, but nothing that is worth worrying about.
Another feature i don't know about til I got it was the sequential mode. Turning a dial on the gear assembly sets the gear stick to a sequential mode, and enables the flappy paddles behind the wheel to change gear. A feature on most other wheels, but one I don't know the G25 had.