Although I haven't sailed on MSC Poesia I have made two MSC cruises on Rhapsody and Melody. At the outset, it has to be remembered that MSC is an Italian company and their ships are not commanded by British officers as, on say, P&O although it has to be remembered that the working crews on most cruise ships come from what is sometimes referred to as third world and these are the people you are most likely to come across on a daily basis. That includes P&O and MSC and I can only say that where I have been concerned I have never met such obliging and helpful people. Two other things I have to say : (1) Some people are born moaners - I have heard complaints about meals etc and asked myself "What are they complaining about?" (2) A holiday is what you make it. for example I found the evening entertainment too repetitive with a fixation on what I personnally called dancing and prancing. So I rarely went. But many people went every night. That seemed to be what they enjoyed. OK. Not quite the high standatd you might find on P&O, but then look at what you paid for. There was plenty of other entertainment during the day and I cannot complain about a single tour even when we had to be escorted by a police /military convoy (Egypt). At dinner, we had lovely companions but I do know some who have asked to change tables - were there disagreements or was there a langauge difficulty. I don't know.
As for the important item of food - Some complained there was too much Italian food (well it was an Italian ship) while others felt there wasn't enough. You can't win them all. My only complaint - I'm a brown beer drinker (bitter, ale, export whatever its called in your neck of the woods) and I just don't like lager. All they seemed to have was lager and occasionally Guinness. If you're like me, I suggest the German wheat beer - looks like lager but tastes like ale. And they had a sensible smoking policy - plenty of no smoking areas but still enough areas for the smokers. Funnily the smoking areas were always packed (smokers and non smokers) with great private entertainment while the equivalent non smoking areas were a bit pathetic to say the least.
Tours : Unless there is somewhere you especially must visit eg Pompeii/Petra I suggest you consider half day tours as in these climates full days can be rather exhausting. In many places, its quite easy to walk into town, take a shuttle bus or share a taxi.
Just make sure you're back on board on time if you go it alone. Our only problem was getting to Genoa to board on cruise 2 (the first went from Malta). If you are travelling from London and you have to get to Heathrow from further afield get to Heatrow a day
before and stay overnight. It does add to the cost but it can save a lot of panic and frustration on the flight day. Also make sure you have pre- booked a seat on the shuttle bus from Milan to Genoa.
Go for it and enjoy your 25th Anniversary - remember to order the cake.