Knoppix is intended to be run from the CD/DVD, or USB memory, to provide a portable Linux system. It does that job very well, being even faster than Puppy or Mepis. The DVD can also be used as a rescue system (it has tools to deal with malware), but the System Rescue distro is probably more convenient for that.

The CD has a good range of software (the DVD obviously more) and comes with all media codecs. It supported all my hardware on 2 computers, including wireless internet.

Configuration of things like the clock and keyboard has to be done at boot time, and can't be done once the system is running. It needs you to enter things like "knoppix tz=Europe/London keyboard=gb xkeyboard=gb". To avoid this, you would have to re-master the disk.

The software list has a few gaps (no accounting software) and it is difficult to fill them. You would have to install to HD or re-master, and there is no repository. Knoppix combines programs from both the Testing and Stable versions of Debian, which leaves the user with possible dependency problems.

This is one of those distros aimed at very specific users. If you are one of them, you'll love it; if you aren't, there's no use complaining.