What's the advantage of a 16 parallel GPS v. a 12 parallel one?

Question

Would you justify going with a 16 parallel GPS if the 12 parallel one seems better in other ways, like software, electronic compass, etc?

Answer 1

Nope. There's a little error in GPS signals so the more signals you have the more accurate you can get by averaging out the errors. But there's going to be very little difference once you get past 12 signals.
You might be accurate to within 6 feet instead of 7 feet.