The Prindle is, in my opinion, the better boat. It's likely heavier, but it has "full-size" hulls. That is to say, the hulls have a lot of volume and go all the way up to the trampoline. The rudder system is more problematic, but that can be fixed or swapped out.

If you can't find a G-Cat 5.0, I would definately go with the Prindle 16. Whichever boat you buy, be sure to check the hulls and hardware thoroughly for signs of abuse.