It sounds like you are focusing on mobile in your post, so I'll try to stick to that.
You may be conflating task capture with task review in describing your conundrum.
As far as capture goes, the simpler the better. And OmniFocus on any platform is higher maintenance than most options. That said, many get along with it just fine.
Here are a couple task capture options:
- Moleskine pocket cahier notebook. Handy for a pocket or purse. Combine with favorite writing utensil.
- Hipster PDA. If you like a bit more organization.
- E-mail. Easiest digital data entry point IMHO. Guaranteed to get to your inbox for processing. Or if you're fancy, you can e-mail directly into an app/service with a mail API, like Toodledo.
Here are a couple of task review options:
- OmniFocus. Since you've already got it. Just don't use it for capture.
- Toodledo. Syncs with a web app.
- TaskPaper. Syncs with a Mac app.
Neither of these lists are exhaustive but it's a starting place. The important point is that your capture method does not have to be your review app. Several input sources, one master list (to rule them all, and in the darkness bind them...). (What? We're not all nerds here?)
Hope this helps. Good luck.