Just installed VectorLinux (ver.5.8 standard final) today. I've used Slack many times since '98 but it has never been my main distro. I haven't tried any Slack based distros until now.
With all that said. I found the install to be a slightly easier version of the normal Slack install. It isn't newbie friendly but it tries and explains a lot of the dialogs you are dealing with. I assume the stumbling block for most will the the partitioning tool.
Once installed everything is pretty polished looking. I like the Lilo splash, the bootsplash, etc. Only minor gripe would be the default window borders.
It does include multiple tools for browsing, multimedia, etc. Flash 9 is installed right off. I would say at the moment the speed is the most notable part of the system.
The package manager Gslapt was kind of hit and miss. It seemed to complain about dependencies on a lot of things. It doesn't appear to resolve them automatically. I probably need more time to play with it.
This isn't a formal review or anything. I've only been using it off and on. Just thought I'd share some first impressions. I've used Debian (and more recently *buntu) for awhile. So I'm not ready to jump ship I just check out anything non-rpm once and awhile. :-D