Omnigraffle opinions

I'm interested opinion on Omnigraffle particualrly if anyone has Omnigraffle on the desktop as I do. Is it worth the expense to have both the desktop version and the iPad version?

How does the iPad version measure up against the desktop version - any features in one and not the other?

I decided to bite the bullet and buy the app. I figure it will be useful for me on the go instead of doing my charts on paper then putting it into omnigraffle on my Mac.

So far it seems pretty good at editing my org charts that I have and it uses Omni Sync Server if you want to export it (and then import it onto your Mac).

Omni Sync Server is not as useful and automatic as DropBox but maybe they'll build out the features because it seems to be in beta for OmniGraffle - for now I have to manually import/export to keep the charts in sync between my Mac and iPad