I've done suit and tux. Own my tux, but it's just the mood I'm in I suppose.
One thought on the packing bit though. With the airlines nickel and diming and the costs for round trip luggage, it may be advisable to rent if you want to dress-up if packing the suit/tux puts you into an extra bag. You'd have to look at that on a case by case basis.
Regardless, you'll feel comfortable either way. Enjoy the cruise.