Well this is a great app… Just a comment, after reading the discussion here about OmniFocus and alternatives, regarding "learning curve", "complicated", etc. etc. etc. – not everybody needs an app like OmniFocus. If you do only errands and your "projects" are things like buying Christmas presents or cleaning up the attic, then OmniFocus probably feels bloated to you and it really is a waste of time and money and you should get another, simpler app.
However, if you work as a freelancer, in the creative business, as a scientist – then you've probably made the experience that sometimes one has to neglect errands to focus on large projects (focussing is about saying "no", a wise man said). The usual to-do-apps are potentially dangerous, because they are especially good at errands, and this can lead to procrastination – instead of working on the "big" project, one does just some errands, goes through the to-do-list and has the feeling of "wow, I am productive!", while actually, one isn't touching the really important, harder (because more complicated) work.
For managing multiple larger projects OmniFocus proved immensely helpful to me. The key is to split up the projects into smaller tasks, sub-tasks, sub-sub-tasks, because these are easier to approach – this way you don't lose oversight nor run danger of getting blockades (and going back to your to-do-list-procrastination-routine). OmniFocus allows for a maximum of flexibility for splitting up tasks, and offers a clean view with its "outline-like"-layout. The limitation of being able to add only one context is actually a very good thing: if you have more than one context, most probably you should split up your task into sub-tasks.
Now some may think it is a waste to spend that much time planing tasks. But for me this helps to decide what tasks are most important and which I can do later (=never). Usually it's the errands that allow for being late or even simply not doing them (well, not a good strategy for paying your taxes of course). Having oversight over your tasks helps freeing up blockades – only that makes research/inventive work possible.
For my needs, OmniFocus really isn't too complicated or bloated. Actually quite the opposite, it's cleanly designed and if anything, it could offer some more features (more options for perspective building)… And well, yes, one has to mention it: OmniFocus never crashes, you never lose data, it's just rock stable.
Version 2 is scheduled for end of this month, by the way…