If hung and supported properly, it's actually better for the playfield than storing it, unless you lay it flat. Storing them on edge can warp them, so hanging them is a cool way to admire the art and preserve the playfield.
I hot glued a string of Christmas lights to my old playfield with the intention of building a shadow box around it and displaying it in my man-cave. I never built the shadow box, but the playfield looks pretty neat when lit up.