The 60% offer appears to be based on brochure rates. In March, I paid $6300 for a S2 for a December 3 Apex cruise. Today, the price is over $9000! Celebrity, unfortunately, appears to be substantially increasing their cruise prices.
in comparison we just returned from a MSC Seashore cruise in the Yacht Club for under $5000 and have booked another for next May for just over $5000.
This was our first cruise on MSC and our expectations were greatly exceeded. While somewhat more casual than X, the YC offered more than the Retreat with very good service. Differences included were a real bottle of Champagne on boarding, a bottle of liquor of our choice, unlimited supply of soft drinks and water in the minibar, an expresso machine in the cabin, a walk in closet, breakfast and lunch buffets in the pool deck and a butler who wanted to escort us everywhere. Yacht Club suites are completely separated from non YC suites and rooms. We did, however, have to pay gratuities and a small cost to upgrade the free wifi to premium. Also, there was no OBC.
One caveat is that while the YC is exceptional (a ship within the ship), we would not want to experience the crowds outside the Yacht Club. The Yacht Club has about 130 suites out of the total 2200 suites on the ship.
We have cruised exclusively on X for the past 20 years, but economics are forcing us to look elsewhere.