Back to OmniFocus. Again.
I like Things. It's pretty and ergonomic. That matters in something you'll spend so much time with. For the most part, I like using Things more than I do OmniFocus, which isn't exactly beautiful to look at. OmniFocus does everything right where it matters, though.
First, Things lacks end-to-end encryption. That by itself should be a deal-breaker for me. I tried to overlook it because I wanted Things to be my ideal to-do app, but I just can't. I think the Cultured Code gang are great people. They have a long track record of treating their users well. I have no reason to think that will change. I strongly doubt they're going through my boring to-do items, but it's at least technically possible, and I hate that I have to trust any company's good intentions. Even if I think they're good people, my employer may not appreciate me storing sensitive information in an unencrypted vendor database. Even more, my wife's a doctor, so HIPAA implies she can't use Things at all for her work unless she keeps all her actions so vague as to be useless. If she put an item in there like "Call Joe Smith back", she could be sued and/or fined for storing personal healthcare information in an insecure location. In contrast, OmniFocus lets you set an encryption password on your data. Then The Omni Group can't access your information even if they want to. If you don't trust Omni's sync server, you can sync it with your own WebDAV server.
Second, Things's search field requires you to type exactly what you're looking for. If I have an item named "Do foo and bar", searching Things for "foo bar" won't find it. OmniFocus will. That's bitten me more times than I'd like, usually when I can almost (but not quite) remember how I phrased a task. Sure, I could just type "foo" into Things and then scroll through the results into I see "bar". I bought a to-do app to offload that mental grunt work.
Finally, it shouldn't bother me so much that I can't check off a repeated task in Things before its start date. It does. It bothers me a lot. I put everything in my to-do app, including tasks like "text my distant friend, Joe, every month". If he and I talk today, and I'm going through my weekly review tomorrow, it'd be nice to mark that as done even though I'm not "scheduled" to chat with him for another 3 weeks. Things won't let me unless I'm willing to dig into the task's repeat settings. OmniFocus doesn't care. It's like "Oh, you're done early? Cool. I'll remind you in a month!" Things users have been requesting this ability for years.
I'm back to OmniFocus. It's not as pretty to look at, but it does everything I ask of it. I wish it had Things's gorgeous interface, and I miss being able to add sections and notes to projects, but I won't trade encryption, better search, and smartly repeating tasks for those features.
I have a note to myself: stop looking for a better task manager than OmniFocus. While it won't win a beauty pageant, it's the best app for helping me get things done.