I tried water-soluble oils for the first time, and girl were they a challenge! I ordered them a few weeks ago for an upcoming trip. They seemed easier to travel with since you can't fly with solvents. Everything I've read said you shouldn't use water as a medium, so I was hoping they would be buttery straight from the tube, and I wouldn't need any medium. (Again, because of flight restrictions.)
They were gummy and unfamiliar, and the pigments and luminosity are different than what I'm accustomed. It doesn't mean they're a bad medium. It just means I don't know how to use them yet and need some practice before I discover how to use them best. I kept this little scene from my living room window pretty abstract, but I'm hoping to lean more impressionistic after I figure out how the heck to use these paints!