Hi Amistad, and welcome to cruise-chat.
Imperial Majesty is unique in that its only ship is a converted 1950s transatlantic liner. Don't let that scare you. The ship, Regal Empress, is a wonderful, friendly liner with fabulous service to match. A two-night cruise on any line will not give you the true cruise experience, yet this is an opportunity to sail on an ocean liner without breaking the bank to do so.
She happens to be my favorite ship still operating out of the U.S., if you couldn't tell.
One word of caution is to choose your stateroom carefully. I know it's for only two nights, but you still want to be comfortable. Definitely avoid A- and B-decks. The cabins on these two decks are tiny and many are hard to find. Upper Deck is generally fine, with some exceptions. I'm happy to help with cabin selection.