And it is tricky to find a new tactic when you run R@G simply because Princeton is half inside, half outside, and no other tactic caters to a pure guard oriented team(as much that is). I have first hand experience of blindly switching tactics when I feel I am becoming predictable, and this occurred in Game 3 of the finals, and I won it because of that, because they ran a 2-3 when LP is the only tactic I've ever had, and I beat them with a Princeton.
I will offer this. Only run a different tactic if you know they will 3-2 zone you, and if you have lack of confidence in winning going against a 3-2. I would recommend PTB if you decide to switch, but Princeton could work too, but only if you have a PF who can shoot.