this is interesting, you are saying that hiercarchical outliners don't work with lots of projects while I was thinking that's when they might come into their own! I have few projects and so have little need for a project/action link but I was thinking this might be different if I had loads of projects. But you're saying the opposite.
I assume something like Life Balance is a hiercarchical outliners. Why didn't it work for you with lots of projects? (also, incidently, what is UI? - I have no idea)
UI is User Interface. I've found tools such as Life Balance and other hierarchical outliners difficult to use for several reasons. I think the most prominant is that with larger numbers of Next Actions and Projects it is difficult to assign the next action to a project. Most tools use a drop down box and picking from 150 items doesn't work nearly as well as picking from a dozen.
I don't know that drop down boxes are really the problem, I think it is really more a matter of screen real estate... I just can't see all 150 projects on the list...
Remembering what I named a project can also be difficult. When I look at a next action, I intuitively know what it is about but I don't necessarily instantly recall what I named (tagged) the project. So finding the name in the list can be a pain sometimes.
When I've played with these tools they've made my weekly review run about 50% longer as I fiddle with putting in all the links... It just seems like wasted time to me so its something I don't worry about anymore...
I'm not saying it's not possible to develop something that would be useful but so far I haven't seen it.
Your idea that we as GTDer users have not made our needs clear on what we want from software tools is also interesting.
Anyone willing to say exactly what they would like?
I'll have a go now:
If I did want a project/action link, the tool could work like this. I just want to see the two lists side be side on the screen: project list and action list. Projects that don't have a next action show up in red. If I want to make a link I just click on the project and then click on an action, and that's it. When the curser is over a project, the next action should also appear. If it was that simple I MIGHT go back to a project action link!
Actually a side-by-side view would go a long ways toward making this easier. So far, I haven't seen an app that does this... But it would make doing the weekly review much easier...
I'd prefer speed keys to mouse clicks however...