You don't just pick up Slackware, imho. You promote yourself to it.
The pros are: steady up to date system; stays put the way you set it. What attracted me to slackware was a guy who had slack on a box for 8 years without a reinstall! I wouldn't advise that always, but that's stability.
You get slackbuild scripts for things like inkscape
The cons are mainly that you do the work. It's not as automagic as some others. A certain level of competence is required, as well as the patience to deal with faults. But you learn loads.
I got very fed up with distros that inevitably fall on their swords after a year or two because of updates clashing with something and you get crazy faults and it all ends in tears and a reinstall. All their fancy script don't do what I wanted to do, etc. I _hate_ setting a box up for myself. I want to use linux, not play with it.