I too was on the same cruise. I had reservations for at Michelangelo for 5 pm every night. I never had to wait. On the second night, I asked the maître d’ if I could have the same table every night which was granted. Thereafter on the following nights, our group of two just check in and show ourselves to our table; no wait at all. This was just for evening dining. Lunch dining on sea days was at Da Vinci with no reservations. There was always a line but the wait was never more than 5 minutes or so.
Most evenings I pass by Da Vinci on my way to Michelangelo. I noticed the line at Michelangelo was much shorter than Da Vinci. For some reason, the line at Da Vinci was always long -- sometimes stretching out to the Piazza.
On another note, we missed the port at Fuerte Amador due to rioting in the area. We did stop nearby in the middle of the ocean for refueling but we did not dock at Fuerte Amador. We got back some port fees. As "compensation", they did throw a "party" on Lido where you can get some free alcohol and canapes. In my opinion, they might as well have done nothing. I don't drink alcohol and I don't like canapes. Some free FCC would have been much better!