Schwyzer is a big fan of self-discipline. He seems like a man forever in search of a cause which he can discipline himself to achieve, be it personal improvement (e.g. running) or social justice (e.g. tithing). In the past his affinity for self-discipline manifested pathologically in eating disorders, but in recent years he has re-channeled it toward veganism. He sums up his perspective on his diet as "radical self-denial on the part of the consumer as a tool for liberating the consumed."
I was struck by his summary because it's almost the exact opposite of how I think about my diet. Being vegetarian rarely feels like denial to me -- and when it does, it's of a passive sort. The operative personality characteristic in my case, the one that sits prominently at the top of my toolbox where Schwyzer keeps his self-denial, is accommodation. Whatever situation I'm in, I tend to accept it and adjust to it. This trait is not without its pathological side, but I've put it to good use with respect to my diet. I've basically gotten myself in a rut where I have trouble conceptualizing a meal with meat in it, and wouldn't know how to cook it if I did. The only times I really feel my diet as a discipline is when I'm eating at an American- or Mexican-cuisine restaurant and there are few meatless options -- but even here, it's less a matter of resisting the temptation to eat tasy meat, and more summoning the effort to find the one vegetarian dish rather than giving up and eating an unappetizing meat dish. Where Schwyzer would urge an aspiring vegetarian to think of their new diet as a sacrifice for justice, I would reassure them that once they've done it for a while they'll get used to it and it will come easily.
The larger lesson I would draw from this is that a strong personality-determinist view -- a "Nietzschean moral psychology" -- can move too quickly to its conclusion. Even if our personality traits are relatively fixed, any given macro-outcome may be reached by multiple pathways suited to different personalities.