I agree with DrJJWmac. It's easy and glamorous to do the collecting part. But you collect and hoard everything in your mindsweep. After a while, you'll have filled up your OmniFocus system with all kinds of stuff - some relevant and some that is just debris.
Doing the review is like spring cleaning. You declutter and viciously delete any projects or tasks that no longer mean anything to you. Renegotiate with yourself about your projects. What's worth keeping? If I keep this project, am I willing to spend time on this project in the future? Will the amount of effort provide enough of a reward if I complete this project?
Imagine being a pack rat and hoarding all kinds of stuff in your house. Your house gets so full of things that you don't want to let go. But you get to the point where all your stuff overwhelms you. Every room is full. You can't navigate your corridors. Your friends joke that your house is more of a warehouse than a real house.
You'll eventually get frustrated, roll up your sleeves and start decluttering. Look at one thing at a time with a clear mind and determine what's worth keeping. I know I had tons of Happy Meal toys for my kids that I never even opened. I had books that were no longer relevant and belonged in a used bookstore where someone can use it. There were baby clothes that my wife kept for sentimental reasons. We finally donated it to the Good Will shop.
When my wife and I finished decluttering, we felt so much lighter and relieved when we finally saw everything in its place.
You'll need to do the review process and become your life editor. Delete, Delegate, or Defer. If you want a clean house, you'll need to declutter. Afterwards, a weekly review will help you keep things under control. Even now, I still remember to do a weekly cleaning in my house. Otherwise, I'll return back to the same cluttered state I was languishing in before. So, do your weekly review, prune the trees and keep everything under control.
Remember: the secret ingredient to OmniFocus is the Review process. I used OmniFocus for iPad to help do the review process. This helps a lot.
Here's an article about rebooting OmniFocus.
http://www.asianefficiency.com/task-...nifocus-setup/
In any productivity system (Franklin-Covey, Do-It-Tomorrow, GTD, AutoFocus, or whatever system you are running), I think reviewing and editing your commitments (goals, projects, tasks) is essential in keeping your life manageable. Otherwise your monster will outgrow you and you run away in fear.