My tendency is towards stability, so I avoid "testing" but it looks like it's a bit of a different deal with VectorLinux. Just out of curiosity, do you normally upgrade most packages that come from the testing repository?
I'm very selective about what I upgrade with a package from /testing. I do keep my eyes and ears open about what's going on in the computer world and usually have heard about security risks. The risks I'm most concerned about would be in my browsers and in the kernel. If a serious risk is found in the kernel, I would expect upgrade packages to be available in the repos. Firefox and SeaMonkey need security fixes from time to time and I upgrade them as soon as a package is in the repos. Opera is my principal browser and my e-mail client and I upgrade it as soon as Opera puts out a new version. I get this from Opera and don't wait for a VectorLinux package. Opera is very easy to install when downloaded from opera.com. Flash and Adobe Reader also have frequent security problems and I install the updates directly from adobe.com. They are also very easy to do and don't need VectorLinux packages.
There are some programs where I'm always wanting the latest features: Scribus, Inkscape, Gimp. I usually upgrade them as soon as a package goes into the VL /testing repo. Not only do I want the latest features, but I also feel a certain obligation to test these programs so that they can get out of /testing as soon as possible. I usually *don't* upgrade other programs that are in /testing. I wait until they're in the regular repos.
I use three computers that have VectorLinux installed. My older 1.3 GHz Celeron desktop is the sacrificial lamb and if I'm uneasy about a new package in /testing, I install it there first. If nothing breaks after a bit of my testing, I put it on the other two computers.
I'm just wondering if I do enable testing, will I find myself allowing all (or most) of the updates as I tend to do now.
You don't need to have /testing enabled all the time. Just do it once in a while to see what's available and be sure you notice what repo the package is in and if you have a good reason to upgrade, do it. Then disable /testing and run Update again so that you don't see what's in /testing.