I keep meaning to do some tests and never get around to it.
Taking some of the glo-flex appart, I think it uses basically the same GID material as the extreme glow (at least it looks like it), HOWVER, it has the reflective film on top. This blocks both the charging and the glow.
That said, there is a certain value to the reflective material as well and even a small amount of light does allow the object with the glo-flex to be seen.
And it does give off a fair amount of glow for a fair while (very scientific, eh).
-john