are the perks for Concierge Class on Mercury. My honest opinion, after being on a similar cabin on Century, is that the perks are all that differentiate the Concierge Class cabin from the Deluxe Ocean View with Verandah one deck down, so you need to determine how important these are to you. The cabins and balcony are the same size in each, unlike the M-class ships where the Concierge Class cabins are somewhat larger.
One difference is that you'll get an extra cruise credit in Captain's Club, which is the main perk we were after. Some of the other perks were very nice, some were just OK, and a couple of others didn't materialize (but those were very minor, IMO).