I'm trapped. When DDI came out I subscribed., and after having it for a while I made the choice that I'd rather pay a monthly subscription and get everything (with errata) and the tools and not buy the books (that quickly needed lots of errata). That said, I'm in multiple 4e games, and unless I go buy all the books, I'm paying.
That said, WotC has consistently underperformed on the digital side, and right now the magazines are dwindling. They just went back to full mag PDF, and the size is minimal compared to what it used to be. I may have missed CB update notes, but as far as I can tell there hasn't been any in quite some time. Others have mentioned how the monster builder doesn't use the current game math. The compendium is the only part that I think lives up to what it should do, and that's a fraction of the total package.
Frankly, I'm excited about playing Next as well as other editions, but I've learned that I can't trust WotC's digital offerings so I'll be buying physical books and not paying them a monthly fee. That'll be a good time to pick up the 4e books I'm missing on the used market, as well.
TL;DR: Paying, feeling trapped, won't trust WotC digital again.