Other. I don't consider what I do as faction hopping in the sense implied by the poll options. I started out on red, but after two years I got fed up with the faction and the prominent players on the campaign I was homed on.
I switched to yellow. It took me a year, then I just stopped pvp for a while.
Some friends got me back in, now on blue.
I play on yellow and blue currently. What faction I play is not depending on external factors (current zerg faction or night cap faction, or population distribution), but only depending on my personal mood/preference.
The only thing I can say for sure is that my EP chars do not ever set foot into cyrodiil any longer
Most people seem pretty diehard to their faction, and I seen crappy people on all sides, still it wouldn't surprise me if Pact had more, from my experience in guild talks alone, pact people are more likely to act superior to the other factions, even AD which, canonically, are more likely to be this way.