I'm here to add a more positive view of cruising in a wheelchair albeit that I am not a full time wheelchair user but I do have limited mobility and use a mobility scooter to get around. We did our first cruise with MSC last year and hired a powered wheelchair for me to get around as we had been advised that my particular scooter might find some of the corners and gangways quite tight and I was so glad I did. It was my first time abroad in over 10 years since becoming less mobile and I actually burst into tears my first time ashore "abroad" again.
We chose MSC Virtuosa and unknown to us when we boarded we found out she was full so over 6500 passengers, I won't deny that this wasn't without its irritations but after a day or so we had worked out the best places to find seats etc and which routes around the ship were less busy. Because of my restrictions I'm a huge preplanner, so before booking I'd used the whatsinport website to work out which itinary would be best for me to be able to go ashore and not have to use the shuttles or excursions, and which ones the gangplanks were likely to enable me to get up and down in the wheelchair as obviously the ship rises and falls with the tides and in some ports that affects how steep the gangplanks are. MSC were really helpful with that and allowed me to board via lower decks on occassion going through the crew areas which made a huge difference.
My husband hadn't really fancied cruising before the first one but he absolutely loved the main dining, we both enjoyed the food, and we also enjoyed the buffet - again its a question of timing, being patient, and working out where the quieter areas are (down the very back furthest from the buffet). We had breakfast and lunch in the buffet and main dining in the evening, we ate in one of the speciality restaurants (Hola Mexican) on one occassion and that was superb. My "happy place" was sitting out on our balacony watching the porpoise leaping over the ships wake - I don't sleep well due to pain so I ended up out on the balcony at 3 or 4am just chilling out watching the ocean and feeling so relaxed. We loved it so much that I booked our next cruise in MSC Euribria within a week of getting home.
The second cruise was even better than the first as we knew a bit more about how things worked and so we booked some excursions - one of the excursions we'd prebooked as a wheelchair accessible trip ended up being changed to non accessible the day before we were due to go on it, this was not the fault of MSC who were really good at refunding us immediately and we chose to take a chance using the shuttle instead and that worked out well so we used the shuttles a few times. We are now booked for our 3rd cruise (MSC Virtuosa) early next year to the Fjords which I am really looking forward to.
Pricewise I find cruising exceptional value for money we always book the premium drinks package, not because either of us are big drinkers, but DH likes a glass or 2 of wine with his meal and I get very dehydrated due to my medication (and the aircon on board does dry me out as well), so I drink a lot of virgin cocktails, soft drinks, fruit juice and bottled water. We feel that we get more than our moneys worth from the drinks package and I like just being able to have whatever I fancy without considering the cost.
The ships are huge, gorgeous and have loads of things to do, you can be as gregarious as you want or choose to stick to yourselves, I cannot manage the pools or hot tubs but thats a problem I have at home too so doesn't really bother me.
If you are new to cruising I probably wouldn't recomend a "taster cruise" 2 or 3 nights as they can often be more booze cruisy with a lot of stag/hen partys and won't give an accurate representation of a longer cruise.