ive had mine out for just over a year, i dont notice any difference, only occasionally ill have a little rough idle, no performance difference....
the rough idle gets annoying sometimes but isnt that bad...
id put the screen back in if i still had it, but it was thrown out months ago.

The rough idle, especially on a Supercharged car, can be taken care of if you get all the turbulence out of your intake. A smooth pipe from the cone to the TB makes the difference. Mine wouldn't idle smooth until I did that (with the screen removed).

I tossed my maf screen back in my car to test this weekend. Idle was identical with or without the screen in my intake setup.

I'd imagine it would only make a difference at an extremely high flow rate. I did the calculations on it a couple years back and came out at about 5%. (Used the water displacement method to calculate)

mine idles rough VERY occasionally... its perfect id say atleast 90% of the time

Watching on a Gtech, i noticed a 50ish RPM bounce every 2 seconds or so.

Jason, that 50'ish rpm bounce can be caused by interference. The Gtech is picking up a VERY low-level signal through it'* 12V power wire, 'listening' for the rpm'*. Simply re-routing the power lead may change this, or simply adding a filter to the lead. Sometimes your plug brand or plug wire characteristics can affect this.

No the engine idle bounces too. You can hear it in the exhaust, and see it on the tach.

As of interference, i had a bad ground after some work (it'* good now) and i my RPMs kept climbing thru the Gtech past redline for a while. Those shiftlights @ 1:30am aren't cool.. when you're cruising @ 2000 RPM.

I just took mune off last night. I feel a lil difference.