I think the Sisu sock yarn is cursed. The first time I tried to use it for my Campanula socks, it was a nightmare, splitty and hard to work with. This time around, I was using bigger needles so the splittiness wasn't an issue. Gauge was. Here is red sock number 2. 
This is the one with the mods so that it will fit my hubby's foot better. It is still too big on the instep. The leg fits well. the toe fits fine. The instep does not. I am tired of this yarn. It was supposed to be my colourful, happy project. Riiiiight. Colourful, yes. Happy? Not so much. Therefore I showed it who's boss.
Apparently, Raven is boss. At least he got some fun out of the damn sock.....
