I find that I work mainly within the “Projects” view of kGTD for precisely this reason. At least when it comes to my professional projects, I tend make decisions based on which project feels like a high priority on a given day and what deadlines are looming. The only contexts which feel really functional to me at this point are home vs. work. I have my phone with me most everywhere, ditto for my laptop. Even the errands context feels a little forced, since I tend to plan my errands when at home, not when I’m actually in the “errand” context of being out and about. I guess this speaks to my need for a more mobile implementation, but I really like kGTD and I’m not all that eager to add to my list of things I need to sync. Like you said, I think it comes down to maintaining a tracking system that works for you. If that means relying less on the idea of contexts for deciding what to do at any given moment, I’m ok with that.

Can I also just say how much I love the fact that within kGTD (well, Omni Outliner in general) I can collapse whole projects and just focus on one at a time. THAT feature is what really helps me narrow down my options. It’s like virtually shutting one mental closet and opening another.