I totally agree with many of the points raised in this thread.
I have cut away the mesh on my side panel, front panel and rear panel... my fans are now a lot quieter and push more air.
I have a Spire Sonex case: http://www.spire-corp.com/main/product_ ... rodID=1154
To me, the front panel has a number of design flaws that can easily be rectified with a bit of work. For the benefit of those who have this case or will buy it, I'll go through what to do. It may also give you ideas on what to do with your case.... as each case is different and has its own advantages and flaws.
#1 - When you take off the front mask, you will notice that the front intake fan is attached to the front mask, and not the metal of the case. (it probably looks a bit better this way, and reduces noise in comparison to if it had been mounted on the mesh).
1a - the entire front mask has dust filters on it, including each 5.25" and 3.5" bay, and in front of the intake fan. But they put a hole on both sides and the bottom so air can bypass the filter! Why on earth put so much effort into dust proofing when dust can just get in that way?
1b - the intake fan does not make contact with the mesh on the case when the mask is attached, and therefore a lot of airflow gets lost.
1c - the intake fan is about 20-25% higher than it is supposed to be, blowing air into solid metal for 20-25% of its height.
1d - the mesh allows little air through and makes the fan somewhat louder (when you actually place the fan where its suppoed to be).
1e - the supplied fan is relatively quiet if your system is not too quiet, but if you have a very quiet system you will notice noise from it.
I cut away the mesh on the front panel. (with a pocket knife). I detached the fan from the front mask and attached it exactly where it is supposed to be - making contact with the hole I cut (I cut the mesh out) at the proper height (there were screw holes there, a simple matter of just screwing the fan on there).
Sticking my face down inside the case I notice a huge difference. (system noise and temps fell too). There is now actual airflow coming in from that fan, as opposed to before.
As for the dust getting in, I am not worried about it... I will periodically clean out my system.
The last step will be to buy a really quiet fan for the front intake which I will control with a fan controller.
Here is a pic of the front with the mask off, and my side panel off so you can see it: http://i.imgur.com/DR8jB.jpg
I will add another side panel fan and cut the remaining mesh off too, and will smooth off all the edges and probably add a finger guard to each fan.
The end result is a very quiet pc that has enough airflow