I've been to all of them except Australia '10 (and in that case, I attended the North American SF Convention). I have heard the discussions in the halls as to who's voting for what, and why. Plus, the vote-counts -- published on the Hugo website, for your edification -- do not lie (much).
The Foglios have the vote count, and the name-rec, because they write to the Hugo audience; Tayler's product is 180-degrees the opposite of what the voting base want, which is why he's forever (for sufficient values of same, given the Best Graphic Story award's only been around two years) coming in just above "No Award". Given the active attempt to push SM voters into the pool, this might change this year; but any finish above stone-stinking-dead last for SM will be a surprise. Personally: I'm expecting this to be the year folks decide to just name BGS "the Phil Foglio Trophy", and be done with it.