Of course, it all depends on the person. I'd rather be with a kind, understanding omni than a snobbish, cruel vegan. Now, my preference would be a kind, understanding vegan, but that may not be practical. (Especially since my bedrock criteria is that my future mate be a Christian.)
Some behavior I simply will not tolerate from any person, regardless of eating philosophy. If you can figure out what that behavior is for you, you may be better equipped to figure out whether this guy is worth keeping.
Q: How many poets does it take to change a light bulb? A: 1001...one to change the bulb, 1000 to say it's already been done.