I agree, currently we missing sync & offlines among essential features. But they're on the road - and much closer than you might assume (but even I understand such a position - taking into account our previous 2.5 years of work). Assuming you start using DO4 now, it's quite likely they'll be there before you really need them.
"The community we build today is what will make it a better product down the road, and without that community the product will ultimately suffer." - that's true. Please keep this in mind. We've been developing DO4 inspired by the initial success of its predecessor. We've taken into account all the mistakes we've made in design of v1.X- 3.X. We wanted to make it really the best one. Incomparable. Incredible. And now we see this is quite close to true, even taking into account there are new competitors - I hope in few more months no one of them will be honestly ready to stand nearby.
Btw, yesterday we've been discussing "second system effect" - of course, in context of DO4. I really feel it suffers from it (nice: few posts before I called it "monstrosity" by my own ;) ) - ok, slightly ;), and mainly - internally. It is really complex, and probably, even over-engineered inside. But it's obvious we can make it simpler. We already did a lot to make its front-end enough simple for developers. The simplicity is the result of complexity, not vice versa.
So take it and start using it. Ask us for help. Bother us by questions. Say us why you dislike it. Don't pay for it until you'll be fully sure it worths this. Btw, we're preparing a set of promo proposals related to licenses for early adopters - so if you planned to buy it, don't do this right now ;) Finally, write about it. Right now it's the perfect time to start re-making the community around the product.
And... Thanks for all of you, who've been waiting for v4.0 during these years. It's really pleasent to see some of our old clients are still here after such a long pause ;)
P.S. To proof it's really stable enough, next time I'll talk about how DO4 is tested.