I’ve been chipping my way through the very fine user manual (love having these Omni manuals free in iBooks), but overall OmniFocus 2 for Mac feels like a lot of small refinements that add up to an overall huge improvement. For folks familiar with the latest iPad and iPhone versions, much will be familiar.
The somewhat bumpy road getting to Version 2 is documented in Shawn Blanc's review.
The pricing strategy is interesting - there is a Standard and Pro version, but for anyone using OmniFocus 1 for Mac, the Standard version is a functional downgrade (you lose the ability to create custom perspectives and using the “Focus” mode). Despite the theoretically less powerful Standard version, it’s hard for me to see OmniFocus as anything but a power-user tool. It’s for people who have pretty well bought into GTD or are otherwise seriously managing their tasks.
With Version 2 for Mac the whole OmniFocus ecosystem feels complete (Mac/iPad/iPhone). It’s not a small investment in money or learning, but I continue to get huge returns on my OmniFocus set-up.