I do interior work and one of my most common requests from customers is to "get the compass off the glareshield".  I have punched holes in two panels so far to mount a Pegasus.  Another guy didn't have room for a panel mounted compass and seriously considered mounting it down by his left knee!

 

This may be a bit controversial, but a compass for me is more to meet the FAA regulations than something I'm going to count on for navigation.  I fly with an MX20 and a Garmin 496 with about 3 hours of standby power.  I have a good ol' regular heading indicator and I use the compass to set it, but I "fly the pink line".  So I think a compass that's out of the way and pretty close to the correct heading is adequate.

 

Mike Easley

Colorado Springs