Well, I just recently purchased one of those aluminum cases and they store the disc upright in soft fabric sleeves. I don't see how that will warp the discs or cause any problems. It's in contact with a fabric like material also, unlike cases which are made of plastic.
I believe it is a good alternative. Pretty easy to locate discs and has a massive capacity.
Hope that helps you.
Btw, I'm picking up my case tomorrow. I have only used 120 capacity spring loaded cases in the past, with the fabric sleeves and they work great. Never wrecked or did anything bad to my discs