Mike,
Thanks for updating your post with the response from Princess. I believe you have a very realistic outlook not to expect much in the way of improvement in the areas you described to Princess, despite a professional (?) reply from their headquarters.
We started cruising Celebrity in 2000 while in our early 40's, and have continued to be satisfied with their product over the past 10 years. Now that we're in our early 50's, while we still enjoy their product (we look forward to sailing one of their Solstice-class ships in the near future), we divide our cruises between them and the luxury lines. Looking back over the last 10 years of cruising, I can say it's all about the progression of age and moving upward one step at a time.
Best of luck in selecting your 2011 voyage!