We run a retail clothing store and the majority of our stock gets steamed with a commercial-grade unit before going on display. They are handy for large items, and in some cases faster than an iron. I will give you four caution notes:
1. You need a sturdy place to hang the garment on a hanger while steaming. You tend to tug at it to keep it flat while moving the steam head over the garment, and the direction of the tugs is NOT straight down, so you can pull over some flimsy stand.
2. Plan to burn yourself occasionally. Steam is very hot and very fast on skin!
3. Steamers do NOT do a good job on cottons, linens or other fabrics that take high temperatures on an iron. They just can't get all the small wrinkles out. But they are OK for poly/cotton blends, polyester, rayon or acrylic fabrics commonly used in many women's apparel items.
4. You definitely should use distilled or deionized water in the steamer. Your will have to disassemble and clean out the boiler from time to time to get rid of scale, and using water with little or no minerals in it will make those jobs much less frequent.