No, I don't think that you made a bad choice. I did not like the fact that on our last cruise (RCI) that we did not have that choice. It was 1615 every night. 2030 is just too late fro the second setting.
I go to the dining room about 1900 and ask for a table size that suits us. If that table (location and wait staff) seem to work, I'll book a reservation for 1900 for the rest of the cruise.
If we know that we will late or eating in a specialty restaurant, I'll let the head waiter know. So you are not locked into the "reservation". If you want to change the time, just talk to the head waiter beforehand.
SS Norway (12 times) '85 - '97; Radiance OS 06/01; Island Princess 11/04, Grand Princess 11/04/05, Golden Princess 7/21/06, Golden Princess 2/24/07, Explorer of the Seas 12/23/07, Island Princess 11/15/08