Review: Porteus 5.0
Porteus is based on Slackware, which may be the most old-fashioned, command line-driven distro in the Linux community, including and particularly for installation. Nevertheless, Porteus' developers have come up with a live desktop distribution (with eight desktops for x86_64) that is portable and aims to be persistent. In other words, so much of what Slackware is not -- and does not want to be.
Does your brain hurt yet? Because mine does.
I spent a couple of weeks with three of the desktops - Xfce, KDE, and Cinnamon - and found that, yes, a Slackware-based distro can offer a live desktop that is portable and snappy. But it's far from straightforward to use or configure, and especially if you want to do more than marvel at how slick the desktop looks and acts. Package management, to quote from the Porteus forum, ain't pretty: "Package management (and dependency resolution) is a perpetual issue in this Slackware based Porteus."
And getting persistence to work? Just writing that sentence made my brain hurt yet again; I was never able to do it. Maybe the best way to explain the difficulty is with this analogy: You may be able to troubleshoot how to save changes to a Porteus USB stick so they'll be there the next time, but it's like walking around the block four times in order to cross the street - a lot of effort for something that should take almost no effort at all.