Basically the PAM355 and PAM98 are the same watch. Just a slightly different dial. Both are regular editions, not limited editions.
Movement in both watches is a Girard-Perregaux alarm movement.
Panerai discontinued to the PAM98, so when they wanted to make another new PAM98, they just just tweaked the dial a little so it's not exactly the same, and the end result is the PAM355.
Cheers,
Anthony
This message has been edited by AnthonyTsai on 2010-04-03 08:27:51