Howard, once you get into the bigger yachts, then far fewer members will have owned one or be able to tell the difference between a shallow or deep draft fin keeled yacht in any meaningful way. In a race to windward sure, but back in the real world with a 4 tonnes of water, fuel and stores on board? I have a bilge keeled M31. I spent a week sailing the fin keeled version and the only noticeable difference was down to the folding prop. Otherwise in a blind test I couldn't have said which was which.
Also, 1.8m is 6 feet. Yes a M54 is a big boat but 6ft isn't exactly a shallow draft. Friend has the M54 with a 2.3m keel. He is sometimes quite limited on the South Coast of the UK. On the other hand beating to windward say Baltic to the Solent were the wind seems to be always from the SW, then that extra depth is great.
Pete