Only if you ditch or your boat sinks. And how often is that going to happen, really?
Seriously, GPS takes the "Search" out of "Search and Rescue." Need I say more? OK, just a little: Assuming you have it with you, a GPS enabled EPIRB transmits your current position along with your distress call. This can be important if you are drifting in adverse conditions [probable], and especially if you didn't manage to get out an SOS on the sideband with your last known position. A regular class ii simply transmits your distress call. I don't know why they even sell these anymore.