I only walked small portions of it through the years, but all of it is beautiful, imo.
I would recommend calling ahead on Pohorje (the first mountain if starting from Maribor) around Rogla, and in all mountain huts in Julian Alps (the most popular part for short hiking).
also, as Kocbekov dom na Korošici has burned down last autumn and was an important (and only) stop between Robanov Kot and Kamniško Sedlo, it's probably best to head up into Logarska Dolina and from there climb to Kamniško Sedlo.
there are some serious mountain sections with rails, pegs, ladders, loose stones and steep drops. some probably cannot be avoided, so keep that in mind when planning.
there are some closed sections due to landslides etc., the list is here:
https://stanje-poti.pzs.si/en.php.
planinska zveza slovenije (slovenian mountaneering organization) has a list of all mountain huts here
https://en.pzs.si/koce.php. if you are a member of your home organization with a reciprocal agreement, you can get up to 50% discount on sleeping.
note that some of the huts in the south-west mountains/hills (Trnovski Gozd, Nanos etc.) are only open on weekends and perhaps an extra week day.