The local (Stihl franchised) chain saw shop doesn't even stock it :) It's a fair bit more expensive and everyone just uses branded stuff from the fuel suppliers.
There are a lot of heavy chainsaw users around here - the area has a lot of forestry and the commercial guys buy their two stroke oil in bulk, so the local shop has quite a few chainsaws going through their workshop.
I'm glad I read this thread though, because I've been a little hit and miss on my mixing, and I've realised that I need to be a little more careful. I ran the thing without oil for part of a tank (after I swapped my lawnmower from two to four stroke).