How's the durability of the Crystal? I had two of the original Penguin systems, and the seals broke down and the frame stretched. I'd prefer to go back to the glass bottles.

No issues with the Crystal so far. It's pretty sturdy. But that's the old 2.0 model, looking at the reviews the new 3.0 is a downgrade in terms of quality, in addition to the downgrade of being forced into the proprietary cylinders

Bummer. I loved the glass bottles in the penguin, but I got tired fighting the durability problems. I got as far as researching custom gaskets and shims, and gave up.