I will have to confess that I still distro-hop. I have set up my computer to maintain three linux distributions. However, one is used to check out new distro's, different desktops, run strange experiments, whatever, it frequently changes. Another, is used for distros I like and want to get a little more familiar with. This one probably gets changed out, or replaced if you like, once or twice a year. The last (or actually first) is saved for Salix which I think of as my permanent distro or home.
Why Salix? Let me say something you have heard before or if not you will hear again and again, "it just works". The truth of the matter is, very few Linux distribution in my opinion "just work" rather they tend to be more akin to a vintage British sports car, that is very lovely, but only lovely to own if you happen to be a great mechanic. While Salix is not the only Linux distribution that just works - Debian stable and Centos fit the bill as well, both of these distributions tend to lag dramatically in up-to-date/new software. (Not that it's necessarily bad, but it does tend to be boring.)
So, back to your question: "Is there other Slackware distro's suitable for begginners?" Yes, and they have already been mentioned. But, is there a better distribution suited to beginners or power users than Salix? ...I don't think so.