I've used them fairly successfully. The trick is to make sure you don't spray them too close to your object or cake. Nice smooth and light sprays work best (I practiced on paper to get the feel of it and the look I wanted). You'll have to do a few layers to achieve deeper color. It works best on really smooth surfaces (like gumpaste or very smooth buttercream). I'll agree with what I'm reading here about the sputtering and splotching, but just make sure you wipe the spray nozzle off frequently and you'll find that doesn't happen as often. The blue color on the top of this cake and the starfish were both colored with the Wilton spray color. I actually layered yellow and red sprays to make the starfish color and I was happy with the results. Then I made the dots with gel color thinned with vodka. It's definitely not the precision of an airbrush (definitely cover any surfaces around what you're spraying!), but if you're not in a position to buy one, it makes a decent alternative. Like an airbrush though, practice helps! Good luck!