When MSC first began sailing in the American market, Reception desk crew members tended to be unsmiling and did not go out of their way to meet your requests. It was a feeling of indifference. Room stewards did tend to be invisible. It's hard to remember exactly because our first couple MSC cruises were in 2010 and 2015. Knowing they're competing with American cruise lines, they've up'd their game. Everyone is much friendlier and they're trying to meet your requirements. As for room stewards, our last couple were very friendly and wanting to chit chat whenever we were coming and going through the hallways. Heck, they worked on other cruise lines prior to MSC so they know their role and how to make extra gratuities.
I prefer to pick my own cabin. I study the deck plans and always pick a cabin that has other cabins above and below me. If you let the cruise line pick your cabin, you could end up above or below the theater, pool deck, disco or music lounges, all-night buffet, etc. No matter the soundproofing, you will hear those things if you're just one floor away. MSC changed their pricing scheme last year and their lead prices are called Bella which are Guarantee cabins. For about $40pp more on a 7nt cruise, I'd rather decide where I'll be staying.