>>5444138I use them every day, just not by themselves.
Light watercolor pencils are fantastic for laying down sketches if you're going to be painting over it with actual watercolor later on. Unlike regular pencils, there's no graphite to make the colors dirty. The sketch lines also don't show through the paint, they erase with the water.
I did two or three pieces with watercolor pencils by themselves last year, and I didn't like how they turned out. I felt like the quality of the pieces would have improved if I had done them in either watercolor OR traditional colored pencil, instead of trying to split my focus between them to get something in the middle. I'm sure others could make it work wonderfully, but it just didn't mesh with me.