We have just booked our first cruise on Princess also. We are on Crown Princess Oct 17/10 Canada and Colonial America. We were also unsure. We have done 3 crossings on QM2 and 4 on QE2 and another cruise on the Coronia (Which is now gone). We have travelled on Norwegian,
Carnival (never again) and Holland America. Cunard is of course, very upscale but we enjoy it. We also enjoyed our voyages on Holland America. We have been assured from the boards that if we liked Holland America we will like Princess. We can compare notes later.
I feel that you have made a good decision.