petro, okay, I've read through your post, in two different threads as it turns out, and looked at how you use priorities, and frankly I just don't get it. If you are using OF's contexts, perspectives, its sequential or parallel options, folders, start dates, due dates, and the Focus feature, why on earth do you need to have priorities too? If you've taken the time to set up your projects and contexts in concert with GTD guidelines, then when you turn to the context view, aren't all of those items listed in red in your Due Today perspective your "high priority" items, those tasks that you need to get done today? And the relative priority of your projects, isn't that controlled by you in terms of what start and due dates you use, or change, as you work through your day, along with how you organize your projects and customize your perspectives? And also, if you are diligent about using the GTD Weekly Review concept (and an OF Perspective), aren't you constantly evaluating the relative worth of all your projects, and making the appropriate changes, in order to keep your priorities in line with your short-term and long-term goals?
Specifically regarding those items that you've labeled as Task 1, Task 2 and Task A in your example, wouldn't you just arrange them sequentially in their respective projects by the most important to the least? Then when you are in the Due, Next Action perspective, you would see only those items that need to be done next (your high priority items). Once those are checked off your next priority items would appear, and so on. You could also look ahead to see what is due tomorrow, this week, etc., which to me seems like a priority system, without all of the additional tedium of numbers and letters. Hmm, is that a priority 1 or 2? Or is it 1a or 1b? Well, isn't it all just stuff that needs to get done in a certain order (priority), which OF helps you with by badge color, perspectives, dates, etc.?
Now, I've read all of the pro-prioritization arguments on this forum (most of them anyway), and there appears to be one common thread that runs through them. They are advocated by those who simply want to hang on to the way they've always done things, by those who have never really let go of their old habits (and don't want to), by those who have never completely embraced GTD, or even really tried it all the way through. (Some haven't even bothered to read David Allen's book.) And so in essence what you and those others want is for OF to conform to your old habits--habits that are just far too precious for you to even think about changing--rather than the other way around.
And I've also noticed that you and others have a fondness for the terms "GTD purists" vs "non-purists" as a means to bolster your arguments for OF "flexibility." That somehow those of us who believe in the GTD system, and use it effectively, are these rigid adherents who have drunk a bit too much of the David Allen kool-aid and are thus too blindly faithful to his ideas to entertain other non-GTD ideas.
Well. Okay.
It's been said elsewhere, but I will say it again: OmniFocus is a GTD-based organizational system. If GTD doesn't fit the way you like to run your life then don't use it. Stick with MyLifeOrganized or Life Balance or the myriad of other similar apps out there, and leave OF to those of us who prefer the GTD way of organization, you know, us "purists."