I tried the official solo rules, the ones that come with Fall of Rome basically. First session I thought they made it easier, which is something the game really doesn't need. But I lost the second one. And I really like to only hold one hand of cards.
It would be good enough to have it as PnP. And it's very light. But I play it occasionally, on "heroic" difficulty. And if you like the gameplay of Pandemic (which I do), this one gives a nice quick fix.
Hard to say if it's worth it for other people. I like having some options in light games as I'm often tired by the time I'm ready for some playing.
Do you still think it's worth owning? I've got it on pre-order, I can still cancel.