I used one that belonged to a friend about 15 years ago, or whatever the equivalent model was back then. It looked slightly different. I thought it was very easy to pack - perfect for hiking or a BOB. You can find smaller or lighter ones, but they tend to have disposable filter elements as opposed to cleanable ceramic ones. A filter that's cleanable in the field was important to me, especially for long hiking trips where you didn't know what to expect for water sources.

Compared to the MSR Miniworks filter I use now, the Katadyn Mini had very slow flow, but the smaller size made up for this downside. I also remember that the door to the Mini's storage compartment broke off. They might have remedied the issue by now, but if they haven't, the door wasn't really needed anyway.