I would never think of them as competitors. One is a program, and the other is a web site, so how could they even compete? I love both though! I'm just really thankful that PlantSetp doesn't have chat threads! I'd never get anything done!
I only use the daylily part of PlantStep. I've added in a few wildflowers, but no iris. I should look into the iris part, since I finally have a few named ones. I hope it works like the daylily area.