I have a strange relationship with OmniFocus. I hate thinking about using it, but when I do use it I don't mind it. The Mac version is decent, but the slow startup time of the iPhone app really destroys its utility for me.

That said, after plunking down $80 for the desktop version that I use but hate thinking about, $20 for an iPhone version I never use, I just can't bring myself to spending $40 for the iPad version without being able to figure out if I'll actually use it first (I understand this is more a criticism of the App Store rules than of OmniFocus specifically).