Well, for what it's worth, here's my 2 cents -- since you asked. You say you've "modified [GTD] a bit from its purest incarnation." There's nothing wrong with that, but I'd offer a caution that you don't deviate too far from classical implementation while you're starting out. As with learning any new thing, it's usually best to start learning the "standard" approach first. Then, when you've got the basics down, when you no longer feel like a "beginner", improvisation is good because you'll have a good feel for how the methodology is supposed to work. In terms of the "training" question, I guess it's a question of money vs time. I've been on GTD Connect for awhile now and find its wealth of information and resources plentiful and helpful. While I've not had any one-on-one coaching, I've looked into it. From that R&D, I did a cost/benefit analysis and, for me, GTD Connect was the best choice. I've got adequate time to do, as you say, the diving and learning. If your time is not so plentiful, however, and you have the money, I've heard David Allen's coaching team is outstanding. Finally, I'm a Mac Geek, too, and a user of OmniFocus. It's a fantastic tool.