However, when you disagree with someone, do you just tell them you differ and leave it at that?

It depends, but that doesn't have much to do with this discussion. I at least generally don't downvote a note because I disagree with someone. Typical downvote reasons (for me) are:

• It's a non-Perl question - many web questions are non-Perl questions, even if a program written in Perl is involved.
• The question is too poorly phrased. It requires too much guessing what the problem is. This includes too much bad grammar, too many typos, and bad specification of the problem(s).
• The post is just wrong. (Probably the majority of my down votes fall in this category). This sometimes causes me to downvote every single post in a thread.
• People not reading what they are replying to careful enough, and coming up with code that doesn't meet the requirements given.
• People asking FAQs or trivial things that could have been found easily in the manual.

But most of the time, I don't bother voting. I often have at the end of the day still the same amount of votes left I had at the beginning.

I also know the arguments why others don't downvote for the reasons I do. You don't have to repeat them - but posts that fall in one or more of the categories mentioned above decrease the value I get from perlmonks. Hence, they are getting my downvotes. And I'm not advocating anyone else should use the same voting guidelines.

Abigail