[sdiy] Dual ground planes

[David Ingebretsen]

Is there any advantage/disadvantage to having two ground planes on a PCB?
I've noticed incomplete coverage on a couple of the PCBs I'm working on and
also different coverage for a top ground plane versus a bottom ground plane.
If I put a ground plane on the top and bottom, I get about 99% coverage. I
can see that soldering will be even more annoying to ground pads with two
planes, but is the annoyance worth having the more complete coverage?

Thanks

David