Yes, I would say it is, in part.

When you say "data loss" you imply the data is gone, nowhere to be found. This is the biggest fear, and should be addressed by backing up your data files to an offsite location.

What you fear is more in the "forward migration" area. If cool software xyz comes out, and I am using abc, then what do I do? Ideally, you would use applications that support an export feature, that would put the data in a list format, comma-delimited format for import into other applications, the new cool xyz software. Not all applications have export feature, and if the one you really like doesn't, then at some point when you want to move, the worst case is you have to manually move all that data over yourself. The good news, you have never lost your data, you just have it in two locations, until you find a way or manually move it all over.

This type of thinking, falls into the, "I don't want to buy a computer today, a faster will be out tomorrow for the same or less money." That statement will continue to be true, even when the new computer comes out that is faster and cheaper than what you bought today. The downside of that thinking is, what value or you missing out on by not buying the computer today?

Or, in your reference to your question, what productivity are you losing out on today, by not using a program that better manages your life than a list. (then again, for some, the list may be just perfect).

I would say absolutely not. Undocumented/unrecoverable binary formats are one of the main reasons I won't use any proprietary software unless a job requires it.

My GTD system is also plain-text based, using Free Software (emacs org-mode) to impose a layer of structure on text documents.

That said, if you're interested in using a particular product and are worried about its save format, you might check if it may be saving as XML, or if it can export to XML, both of which features are fairly common today. Or, as scottw says, export to CSV or another structured text format.

Well said. I suppose this goes to the heart of the matter. What am I missing out on by not using proprietary software?

I do use some proprietary software because the features are just too valuable. But the bulk of my GTD/notes system is simple. Text files and paper. I guess I haven't found an application(s) that has enough features for me to overcome my fear of not being able to access my data.

Aaron

I don't think its an irational fear, maybe because I've been there.
I start out with speedscript then geoworks on a commodore 64 then on to somehting on an amiga then wordperfect on a pc then ms word, etc. I've had to export/import documents many times and always lost somehting in the translation that I had to recreate.
I've also used apps like MS money 97 and bought the next version (Money 98) and found it wouldn't import my money97 file and a paid support call to Ms tech support left me with "your file is corrupt, start a new one" so I was stuck running the 97 and 98 versions on two differnet pc's if I wanted accessto my old and new data.
I've made it a standard that my files and software have to be open now and I'm finding that I don't really miss anything, the features of propritary software are somehting I find I don't use often enough to remember how to use them and in the time it takes to figure those features out I could just make something work in an open package.

On the Mac, I use iGTD, I love it. It is a godsend for me. It integrates with just about everything and anything it seems. Your in Mail.app, click on the email, hit F6, and wham, you have a new entry in iGTD w/ a link to the email. On a website, same thing, it just works so well and provides export feature as well. ;)

But, until you find the application that suits your needs it is easy NOT to adopt something other than something like a text file.

TaskPaper uses text files. It adds a ".taskpaper" extension to its files, but those files can be opened in any text editor. (I wish it would open ".txt" files, but that's easily scriptable).

Not at all, I'm the same which is why my application uses plain old xml files (and even when I do add in Outlook support as has been requested, the ability to use xml will still be there).

Locking in your users isn't necessary in my opinion.