Maverick1
Thank you for that clarification, much better than Diamond Club's e-mail.
Its when they talk about "As a diamond club member you will see minor changes to the number of miles awarded on some of our lower fare types..." that questions arise. "Changes" usually means "cuts". I doubt that I will get business class points on an economy only route such as MAN - LHR.
I'll have to wait for further details of what flights will cost, and what I'll get, but the chances of me (and I'm sure others) moving to other carriers or forms of transport will increase, which will be a shame.