Hmmm, interesting question, we've always had really hard water, and always had that problem with mineral deposits as well. Personally, I prefer the metal shower heads and have never noticed a problem with corrosion when using them. On the other hand though, I've had many flimsy plastic shower heads fall apart from the pressure of the water.

While many of the plastic shower heads do have more spray options than their metal counterparts, they both are susceptible to getting mineral deposits, depending on your water quality and whether or not you utilize water filtration.

Your decision should be mostly based on your budget and the look you are going after. On a sheer cost and performance basis the good plastic models come out on top. You can replace quite a few plastic showerheads before reaching the price of a good metal showerhead.

If you are spending a lot of money on a master bath remodel it undoubtedly makes sense to use metal. If you are doing a simple budget remodel of a guest or even a master bath, you can get away with a quality plastic showerhead.

Of course, if you want a regular showerhead and a side adjustable hand spray model you would probably have to go with metal for a more coherent look.

Greg