Blazer, I just got mine. I've fished with a friend that has had one for a year or so. The only time his lost reception was when it was tilted too far back (bow mounted) and once he sat a large tackle bag close to it and it would lose reception while traveling a certain direction.
According to the Lowrance site, you can use an external GPS module, LGC 2000 or LGC 3000, for the antenna on the 522. The internal antenna of the 522 can be disabled using the menu.
I may run both my 520 and 522 off the external antenna of the 520 if I have any reception problems with the internal antenna of the 522.
I'm not gonna hit the panic button on my 522. GPS manufacturers are always making improvements to antennas as the technology becomes available. There will always be some geographical locations with poor reception, and newer and better GPS satellites are ahead.