After many years/visits loving Mama Della's, we had two consecutive bad meals there (4/17 and 10/17). IIRC, my meal was mediocre on 4/17, but all four of us in 10/17 were very disappointed. Not sure what changed, but we will probably pass for the first time in 17 or 18 years on our next trip. Also disappointed that Mythos replaced the mashed potatoes in my go-to beef medallions entree with some vegetable medley a while ago. Last trip, I just asked the chef to make me an "adult" grilled cheese sandwich to go with the always fantastic Tuscan tomato soup.
On the flip side, we tried the Mexican restaurant in City Walk right after opening and the service was horrendous so we skipped it the next trip or 2. Last trip, we tried again and the service was great. Everything we had to eat there was also great. This has made it to our must-do list each trip.
... and a medium rare CBCLT at Cowfish is still one of the best hamburgers I've ever had.