Very few plants actually take root more easily in water than in soil. I propagate hundreds of kinds of plants every year, but Coleus & a few kinds of tropical vines are the only kinds that readily come to mind that I would put in water to make roots, instead of in a pot or in the ground.
Opp, I agree that most cuttings root better and stronger in soil than in water. If I don't have potting soil at the moment, I'll try water rooting. The only cuttings I've had consistent luck with in water are basil and a succulent given to me by a friend. I think that succulent would root in dry air!
