I just thought I would add a follow up having used 2Do seriously for nearly two weeks, and let me say it was a revelation.
Firstly, the checklists feature allows me to massively reduce down the number of lists I needed to keep, e.g. a “morning rituals” checklist would in OF have to sit in a specific project, in 2Do its a checklist in the bigger “Business admin” list, which for me makes management easier.
I also found the ability to add URLs, mail or contact details as an “action” more useful than I thought, adding contact details to a task and then filtering a smart list to show only tasks with this entered creates a custom communications perspective very easily, and on iOS its a “tap and call” scenario
The search/smartlists/tagging features combined allow granular control of what you can see, once you have your head round the syntax for search its pretty simple.
New entries on iOS is much quicker, on the Mac I miss command line task creation, although batch edit on iOS is something I did know I would miss until I had it.
When doing this test of 2Do I purposely only used one tag per item to simulate contexts in OF and had no real problems. I rethought tags a couple of times during the first few days but all now seems solid and settled.
Syncing via Dropbox is fine, no real difference between OF or 2Do for me on that one.
As a (largely) one person web design business I continually run through the same routine when coding, the combination of a list (think folder) per client, with checklists and projects for areas such as admin, coding, seo etc seems to work pretty much as I do so no issues there.
Notes on 2Do are a big + from OF, never a big notes user before in 2Do I found myself using them regularly.
Down side: The big one, archiving. I have created a “completed in the last week” (minus routine tasks) smart list for the numerous one off requests for changes and updates I get daily. This I will print out as a pdf and it can be read by eagle filer and then the tasks deleted, f I need to search (which I rarely do). Design projects can be archived as they are closed when finished but yet to test this.
Reviews: I tend to go through everything informally once a week at least and often daily over a coffee on the iPad, so a formal GTD review process has never been part of my routine, although I can see why some would miss this.
Sequential projects: honestly I missed this at first having come to rely on this feature, in 2Do I just use a start date for whats next and leave others undated, I also pause checklists in design projects if I am working on one of the other areas, so I guess I have got round it OK.
Mail: 2Do integration on iOS is pretty amazing, it is not forwarding, it talks directly to your mail account and acts on the rules set. (it supports regex). e.g. flag a mail on mac watch it appear in 2Do. You can also use URL schemes on iOS to automate or save lesser used search syntaxes for example in drafts then run them with an action reducing the need for lesser used smart lists.
2Do is for me an iOS app first and foremost, the mac app works well enough but is not as polished or pretty as OF. Its akin to devonthink versus evernote in terms of looks.
So, am I happy with 2Do, yes, it suits me and the way i work. Do I trust it, yes sort of. I have a nagging feeling OF is better written, and more professional, but I think I may for now be a 2Do convert. OF has taught me how to think about organisation, and I have learnt a lot, however for me 2Do seems to have been built by a lone developer for lone developers, where s OF has a broader focus and probably suits a wider spectrum of users.
Ironically as someone who loved the “creating flow with OF” book, and used this system, largely recreating it in 2Do was easier, resulted in a simpler schema of list/projects etc with the same end result :)