I'm with Andy on this, as I remarked on the 40tech page. It's a bit hard to articulate the problem, but the basic approach of Producteev is not the same as GTD.
Because labels are not global, do not cross workspaces, they are pretty useless for me. So, I tried setting up workspaces for contetxs, e.g. @office, @home, etc. I also set one up for projects, which require more than one "next action."
However, with my GTD process, I need to have tasks remain in the “Projects” context but also appear in another, for example, “@Office.” To illustrated, I have a “prepare for Baltimore trip” project–set up with a label, the next task for which is “gather paperwork.” If I place that task in my “@office” context, then it no longer appears in the “Projects” workspace--which means that when I review that project, I cannot see all of the actions assigned to it anymore.
I need to see ALL my tasks in the projects workspace, even after I move them to their relevant context. That’s how I work GTD and I don’t think this method accommodates that.
I may try to do some other way to make Producteev work the GTD way, but I think using labels rather than workspaces for GTD contexts is going to be clunky.
I currently use Jello.Dashboard, an Outlook add-on, to do my GTD. I like the idea of a web-based app and Producteev has some nice functionality, but I'm likely to give up on it in a day or so.
I recently came across "Remember the Milk" and may try that, as there seems to be a good GTD tutorial:
http://blog.rememberthemilk.com/2008/05/guest-post-advanced-gtd-with-remember-the-milk/