Hi. I was on the same cruise as you. I am sorry you got stuck in a sucky cabin!
This was my second time with MSC and while I am planning another cruise on the Meraviglia, I will not be back on Magnifica. Maybe it is just too small for me, although I really liked all my cruises with Majesty of the Sea which is also a smaller ship. And yes, finding public bathrooms was a pain! They are not marked properly and I had to keep asking staff.
My son and I had the non-alcoholic package and every venue we went to for drinks was great. Bar service was one of the best out of any cruise I've been on.
I agree with your overall assessment of the MDR - I wasn't crazy about any of the entrees, the appetizers were fine. I do not like sweets but my son said the cheesecake was good. As a mafist (pescatarian+poultry, basically no mammals, and yes, there is a name for everything nowdays), I found that my body was craving protein other than eggs and salmon, and there wasn't much there unless i wanted to eat the dry chicken breast. Again, I did not have this issue on the Mera, there were more choices both in the buffet and the dining room. Plus the low ceiling in the MDR made me a bit uncomfortable.
Our room was tidied up *at least* 3 times a day, and that was very impressive. That was actually better that the other MSC cruise I was on.
The gym was surprisingly large and really nice. The Spa area (I purchased the Aurea experience) was ok but not enough variety and I really only used it once vs. on Mera where we went at least once a day. Again, maybe it the smaller ship/lower ceiling, but something was off for me.
We did not partake in any entertainment so I cannot comment on that.
I do think it was a good value for how much I paid (and we were upgraded to a balcony from an inside) but I would not do it again.