I've been using 5gal SIPS all winter with solid success been averaging +/- ~6oz per sip harvest...love me some sips!
My experience has been straightforward and nothing crazy... I use the same dirt I mix for my soil bag grows. 30% organic soil, 30% perlite, 30% SPM... with handfuls of kelp meal and worm castings thrown in as I fill in the bucket.... for SIP's, I line the bottom of the bucket with perlite for draining before I fill with the soil mixture... i love SIPS! hope you do too-good luck!