I wore out my beloved Conair ExtremeSteam, and bought another, and the new one didn't get quite hot enough, so it spit out water instead of steam. I now have both a Rowenta and a Sunbeam (one at home, one that travels), and I like them equally.
Be aware that a steamer is great for touching up, but if the costume has come on a slow boat from China crunched up in a box, you are going to have to iron it initially to make it look right. Be sure to read the costume label for the material, and use the correct heat setting. Put a thin damp cloth (like a man's handkerchief) between the costume and the iron, and iron on the backside of the material.