Thank you everyone for the replies. I have decided to go ahead and get the PLB first, and then perhaps by this fall when hiking season comes around again, I'll get a GPS. For this upcoming hike, I am really more worried about an injury than getting lost. I do have a compass, paper maps, and my iPhone with some good GPS software and downloaded maps.

I'd still like to get a GPS for reasons that a few have mentioned. Mainly ease of battery replacement and not draining the batteries on my primary communications source.