Wow, I saw your post and checked it out as I really wanted to do the April T/A cruise that you did. I'm glad for you the cruise was good, even if the Grand is no longer so grand. Did you have rough seas besides the one tender port? Any problems with any of the ports, especially Brazil & the African ones?
I ended up doing the repositioning cruise on The NCL Dream from Valparaiso, Chile to Boston in April. We encountered some of the same problems as you did, even allowing for a lower expectation for NCL vs Princess. The ports and Panama Canal transit were very good as was the weather.
Just this week noticed a deal on the Grand Princess>London to 9 Norwegian ports and back to London on June 19. I was excited until I checked on the air & tranfers which were more than the cruise, which seems to be why the cruise was on sale. Now after reading your posts, I don't feel as bad about not going.