At the time I was using org-mode for pretty much everything : taking notes, keeping my contacts list, monitoring the time spent working on different projects, etc.
But these days, even though I still think org-mode is one of the most powerful notes taking system out there, I don't use it anymore. Now I am using a mix of hamster and zim. Here is the list of reasons that made me switch from org-mode:
1. I don't use emacs anymore.
I am not going to start the old flame war about emacs vs other text editors, but the fact is that org-mode is only useful for people who know how to use emacs. I don't like to use too many different tools, I am already currently using gedit, netbeans and vim. Having to use emacs at the same time confuses me too much.
2. No integration with gnome
This is specially important for time tracking. I need to be able to see at every moment the task I am working on, and be able to change it in a few seconds. With org-mode I had to switch to the workspace where I run emacs, then enter several commands to see the current task and changing it. Very often when working on a task I would forget to start or stop the timers. In contrast, hamster always show very clearly in the gnome bar what I am doing and the time spent on the task. A simple click and I can stop the task and start a new one.
3. Too complicated (but this is related to the point 1)
Not really a problem for people who use emacs all the time, but when I use it only for org-mode, then I spent many time simply learning the commands. Getting Things Done is all about spending time doing things, not learning about how to do things.
4. Zim organization of files is much better for my needs
The most important thing that org-mode (and zim) got right is that all the data should be stored in plain text files that can be read and edited by any text editor. This way I can always access my notes no matter where. Now the problem with org-mode is that if it works very well with one file per project, it doesn't scale well for wiki style notes where you have many small text files linked to each other. Zim on the other hand make it super easy to have as many files as needed. Each file is automatically added into the ~/Notes directory, which is exactly what I want. On the left
So, here is the typical way I use zim and hamster :
Every morning after I turn on my computer (and I am done reading blogs and emails), I click on the hamster notification to start a new task. The timer always remind me of what I am supped to do, and this is a good physiological fence that prevent me from focusing on anything else that
the current task.
I keep a general Zim note for each project I am working on, that mostly look like a TODO file. Before I start to work I can read it and see what are the important things I should do.
If I suddenly have an idea or find a link that would be useful for a task that is not the one I am working on, I open zim (takes half a second) and add the idea/link in the relevant note.
When I find useful general informations, I add then into my personal wiki that is also managed by zim.
Every time hamster reminds me that I have been working for more that one hour on a task, I allow myself to make a pause, and eventually switch task.
At the end of the day I can review the total time I spent working during the day.
In the end my workflow is pretty much the same as before, but the overall experience is much better than it was with org-mode.
Now of course there are some things I wish I could get from zim / hamster
This is the killer feature of org-mode, and to be honest the only reason I still sometime turn on emacs these days. org-mode just make it super easy to edit tables.
2. Calendar integration
I would love to have gnome automatically parsing my notes for entry containing dates and adding them in the calendar. Once again org-mode had it almost right, except that they don't care about gnome or any other desktop. For them the working environment is emacs.
3. Better wiki syntax and text editing
Disclaimer : I am a fan of restructured text, and I wish that every wiki would use its syntax.
Being a programmer, I feel more comfortable working with mono-spaced font, with if possible a way to automatically format the lines to 80 characters. Currently zim don't allow to edit the notes directly in plain text, and I understand it is the better option for most people, but that is one of the cases where I think more choices would be good.
So should you use org-mode or zim / hamster or something else ?
My opinion: If you already use emacs a lot (and if you like it), then go for org-mode, you can do pretty much anything with it and it can be quite enjoyable to use.
If you don't like emacs, and use gnome, then go for zim/hamster. You can get 80/100 of what you get with org-mode, and you won't spend much time learning it.