I realize it's heresy, but I never even look at the compass. I am a GPS man. I know, you respond, "But what happens if the GPS system goes out?" To which I then reply "if the GPS system goes out that probably means all out war, so I have worse problems to think about."
If I really needed the compass, I am sure I could switch off the radio and use the one in the cabin.
Okay further to that, would a radio give off enough heat that keeping it in the navpod would kill anything?
Consider... the main real-world problem with electronic nav aids is not the "sky part" but your own on-board part....
We have had enough problems with our "Low QC" Garmin that I would never deleberately compromise the basic compass-and-paper-charts part of the equation, and I do indeed use the chart plotter when under way -- also our trusty old iBook running GPSNavX.
If you feel the need to place magnetic stuff close to the steering compass, just remember to remove it FIRST when it dies. Once you dismount it and put it away, inside the cabin, your steering compass should be fine.
Of course, your compass has been swung and corrected, and a deviation card prepared, right?
And your paper charts are on-board and not more than ten years out of date, right?
And, back to the "door we came in"...... I have done a recent delivery on a boat with a StandardHorizon combo-vhf/ais. It was way cool.