I didn't see anyone mentioning this in this thread, so I just want to make sure that you are aware that OmniFocus can have sequential actions for a project.

Personally, I often set up projects that are very simple and predictable but still include a number of discrete next actions. By setting them up in advance, I already have the next action in my system as soon as I check of the previous one and can save time by not having to enter a new next action into my system during the process.

An example would be a project of completing the meeting minutes for a meeting that could have the following (sequential) next actions:
- draft minutes
- email draft to chair person for review
- waiting for: comments from chair person
- finalize minutes
- print and mail minutes to chair person for signature
- waiting for: signed minutes from chair person
- scan signed minutes to computer
- email minutes to all attendees
- archive minutes