I love it. I also have a blue one that I got somewhere else. So helpful for marking seams and such.
I have heard that there is a white one - for use on dark fabrics. I have read that it isn't really good. It seems that the white mark takes a bit of time to show. I currently use a Bohin chalk marker. It is okay, but it makes a fairly thick line, and doesn't disappear. I have to be careful about where I use it.
If there is a white disappearing marker, I'd love tohave one.