I agree with all the above comments. When I was on the Niew Statendam last August, I made comments on Navigator app. My stepfather and I never got emails with post cruise survey. I emailed guest relations in Seattle and asked for survey. We never got them. I'm glad I used the Navigator app and I will use it again on my next cruise.
I agree with others who said that the crew who give the best service never ask for a review. I don't mind it if crew says on last night to fill out post cruise survey, as long as it's a quick reminder.