Thanks for the reply David. And though I certainly trust both your and Dave's reputation---- I am a very, very long time customer---- I think as far as this new pricing model goes, I'll hold off on paying into it until I can see how everything works out over a few update cycles. I truly hope my concerns will prove unjustified, and that a few updates from now it will be a thriving game engine with a thriving multiplayer and moding community.
Edit: One other possible suggestion, what about including a couple free data pack upgrades with each scenario pack purchase? There could be a reasonable increase in price if necessary. This would go along way to assuaging my queasiness on the model, as it would allow one to keep playing certain scenarios that one is interested in at the time. It might also be the case where a data upgrade fixes a bug particularly prominent in one module, but doesn't do all that much in others, so there doesn't seem much need to upgrade the other modules. Above that, it would be a way for one to support the engine by buying new content, keeping those portions of the content you are currently interested in updated, without making the user feel he is "paying for a patch" (even if that's not what one is formally calling data pack upgrades.)
That is more for Dave to decide but we plan never to be in this spot again were we do not have the serial numbers for current customers. Any good company will tell you we want to make our developers and hence our customers VERY happy. Map66 or anyone else we are here and willing to discuss any idea or issue someone may have.