This is another tough one for CW. As I said before, only CW knows what it costs for the add-ons like AD2 - but nothing is free that's for sure.
On one hand you have people who want the "core" and "functionality" as the focus. On the other hand lots of people love that they can get a program like Melodyne, AD, BlueTube etc thrown in as part of the upgrade. There's a real temptation to do the calculation and decide that the upgrade price is worth xxx because the cost of add-on is xx. But if you weren't going to by add-on xx in the first place you're just rationalizing a new toy. DimPro, Rapture etc are a little different as CW owns them and it seems like they're depreciated enough that it's probably null cost of the upgrade.
But it seems that the add-on path is getting a little saturated. Most people (esp those using a "platinum" level) already have more plug ins and stuff that they can actually use. And I see more and more threads about simplifying and streamlining personal workflow so you (I) dont spend (waste?) time messing with 10000 plugins.
Personally, I like stuff like the CA plugs as they sorta use what is there but make my life easier with how good they are. And I'd like work on the staff view, varispeed, etc vs 3rd party plugins.
Not sure where the membership will take us - but should be fun finding out. I have to believe that there will be more updates to the actual SONAR than new "bundles" but only CW knows. Will be an interesting year!