We travelled on the MSC Poesia in September and as first time cruisers we found it great. Obviously we have nothing to compare it with, but we read up on reviews before we went and found they varied greatly. I think at the end of the day it is all down to your expectations.
The ship is new, beautiful and spotlessly clean - always someone cleaning somewhere day and night! Cabins quite spacious and comfortable - we had a window cabin - no balcony and this was fine for us. I don't think we'd have had time to go on a balcony anyway. I liked having a window to see where we were and get daylight, especially in the mornings.
Food was great - buffet at lunch didn't vary much but there was plenty there and it was all pretty good. Most days they were cooking a fresh pasta dish out by the pool at lunchtimes, this was lovely and saved queueing at the buffet. If you go to the bar during lunch there is free tea and coffee available - they don't publicise this but it is there.
Dinner was also good - about 7 courses - always italian, but good italian food.
Breakfast was a choice of buffet or restaurant service, or a light breakfast in your cabin.We ordered tea and coffee to be delivered to our cabin then went up for buffet breakfast later.
We found the waiting staff were fantastic. We took our own wine and paid a small corkage on several occasions and they didn't seem to mind at all.
Afternoon tea - cakes and biscuits were good, but queues for the drinks were a bit ridiculous.
If you have a teenager with you they offer a special reduced rate drink card which is worth having and putting all your soft drinks and water on the card during the evening meals.
We enjoyed the shows every night, there was plenty of entertainment and things to do - having 2 small children we didn't get chance to try much, but I can't imagine you could ever get bored.
The pool area was crowded and the jacuzzis always full (mainly because the weather wasn't brilliant for us so the pools were not so enticing as it was a bit too cold).
Kids club ran from early morning til late evening. You could leave your children while you go ashore if you like.
We didn't do any organised tours as we didn't want to be tied down having the children with us (ages 1 and 3) but all the stops, with the exception of Istanbul, had quite good tourist info at the port when you arrived and there were always taxis and often horse& cart tours or little tourist trains running from the ports. Izmir was one of my favourite stops and we enjoyed the Bazzar there. In Istanbul the tram is easy to use and stops at the main points of interest. Signs are in English inside the tram to tell you which stop to get off for Grand Bazar, Spice Bazaar, Blue Mosque, etc.
One thing I would recommend, is to plan to get a taxi when you get off the ship at the end of the week in Venice. Although a free shuttle bus is provided by MSC the wait to get on one was far too long and dissorganised, not the way you want to finish your holiday. We paid 15 euros to get to the bus station where you can get buses or vaporettos and there is a left luggage here too if you are stopping for the day in venice.
I hope that this helps someone planning a trip and if you do go, don't expect the QE2 just expect the Poesia and I'm sure you'll have a really lovely time.