I've go the PDAir case, and I like it a lot, particularly with a few modifications, but it does seem to affect the (already poor) GPS reception.

Do you have any measurements, photos, etc. of exactly where the antennas are? I'm considering cutting out a chunk of the metal on my case (I may replace it with plastic, or leave it empty), but I'd like to have a better idea of what to remove.

Thanks!