I would only need half the fingers on one hand to count the number of times I've used the free Diamond breakfast since it was first introduced, and my travels are exclusively for leisure. I'm normally gone for a week or more at a time, so only 2 of every 7 days would potentially qualify. And most of the time, I'm either booking on Fairmont Gold, or some suite that comes with breakfast anyway at that particular hotel. I suppose for some travel patterns, it might be worth something.

For the SNUs, I don't really consider them a Diamond benefit. They're a Platinum benefit, and the more points you earn, the more SNUs you receive. If they were to remove the Diamond tier completely, or double the points requirement to receive it, the SNUs earned would still be the same.

Good to know about negotiating better deals. My only experience since Diamond was introduced, is as a Diamond member. So if I've managed to get better upgrades because of it, then that's a good benefit, although it's difficult to measure without seeing how non-Diamonds make out when booking at the same properties. Booking for a variety of clients, you would be in a unique position to see those differences .