I used to do the 7 Habits style but found that I was constantly moving stuff from one week to the next when I didn't finish.

I switched to GTD a few years back and am much happier. I won't claim to be a perfect GTD adherent, but the brain dump + 0-inbox cycle theory works great in practice. I no longer constantly worry about "I need to remember to do X" since I have set up tools that allow me to place all action items in an appropriate place.

While I used to try to always do stuff quickly to get it out of the way, using GTD style to get it persisted somewhere allows me to be sure it's captured and then not care if I never get to it.

Where GTD falls down for me is that I have so much stuff in there to work on that it just can't prioritize for me. But it's not supposed to. My challenge since adopting GTD has been figuring out what context to be in.

I like TFA's comments about augmenting GTD with his technique to help decide what to work on. Context selection is prioritization and he has found an interesting approach to achieving focus that gives you power to ignore interrupts.

I also learned a lot from GTD like getting things out of my brain, next actions, and zero inbox. Te challenge I found in GTD is exactly what you're pointing out - theres so many projects that it's hard to prioritize and sid you do your next actions based on context it doesn't ensure you're working on the most important things. But I still think some people with certain types of jobs can make GTD work, especially if you have a less creative job and just need to get a ton of tasks done... and you like to work that way.