I registered DT ages ago because it is a great product. However, I've found that it's ultimately overkill for what I needed--even though it is über-cool.

The main reason you throw stuff into DT is so you can index it, organize it, and find relatedness--the main feature of the app is the little drawer that shows you similar files. Most of the time, you just don't need this unless you have THOUSANDS of files, as you would if you were, say, researching a dissertation. But even then, DT gets better the more you subdivide and organize those files into subfolders, so there's always a large amount of effort involved in organization in order to reap the benefits of the semantic classification. I had to ask myself whether it was worth all that effort (syncing, importing, exporting, capturing, organizing) to get at those connections, most of which I knew about or could have figured out anyway. It wasn't. There's also the fact that learning to make connections, see similarities, etc., is a skill unto itself that's worth cultivating.

So to my mind, from a GTD perspective, tools like DT are actually -not- what you want to be using b/c they a) require constant tinkering b) encourage an over-stuffed filing system and c) replace decision-making (what do I need this for? is it actionable? etc.) with deferral (I'll just let DT index it...)

I've come to the same opinion about wikis, which I used to spend lots of time maintaining and adjusting. Ultimately I spent more time fiddling with the wiki, throwing stuff into it, and paging through it than I did doing my main job, which is reading and writing. YMMV, but in the end I've settled on plain old index cards, just like in high school. This isn't a knock on DT, which is a great app and for which I've put down my $40; it's more a response to the endless search for the 'all-in-one' app that does it all, etc. etc., especially in the context of GTD, which is all about actually looking at your data rather than relying on search to look at it for you.