Have been a member for about 10 years, and don't find the discounts particularly exclusive or worthwhile (or expired).
However, as a 'club' you will only get out of it what someone/you are willing to put into it. I can complain about the magazine content, but can't really offer anything to it, so I can't really blame them for putting in the only stuff they've got.
I mainly use it for the events and track days. Would happily forego the magazine as there's very little of interest to me in there, and the latest, more up to date info is on the forum/website.
Most dealers claimed to have included the BMWCCGB discount in any price they charge, or say they've opted out and run their own loyalty scheme.