I have too many guitars, want more, none I want to sell...so I'm out of room. When I was a kid, several people told me it was best to keep the guitar in the case, and store the case vertically/upright, not flat (e.g., under a bed lying flat), not horizontal (on end, handle/locks up)...I've always kept the guitars upright and never really thought about it until I ran out of space At present, I have them upright (vertical), body at the bottom, handle toward the wall, leaning on another wall, stacked like books on a shelf, leaning on each other. This takes up too much space, not to mention having to move several to get at those at the end! I have a space that will allow me to store several guitars (in hard cases) horizontally, on edge (not flat, handle/locks up) instead of vertically. Any concerns with this?