Yes.. I agree with you about HSS and the flash output. Lots of options out there... I like that the Interfit S1 can be used on battery or with the included A/C adapter/cord. Several nice reviews about the strobe. Not certain which direction I will go just yet. Choices!
What camera are you using currently? The S1 remote doesn't work on my 7D2, which suggests it may not work on some other newish cameras. Dual AC/DC power is definitely a plus, but I'd ask myself whether it's worth the price of two Rovelights/AD600s (or one of them + a bunch of batteries). The Interfit S1 is very good on paper, but it has a few quality issues in my experience with it. Not saying the others are any better, of course.
As far as whether the lights will have enough output through an octa in full sun, see here: http://photography-on-the.net ...showthread.php?p=17589413
Just to increase the chaos, I'll also add the Phottix Indra500 to your list.