I can't say that I have any hard or fast rules. Generally, though, I do like to see people's reactions to things, particularly on controversial topics. It's true, many places have low quality comments, so if they're particularly vitriolic, I might only scan a few top comments to get the gist. I like to play devil's advocate sometimes (often to my friend's chagrin) so if I can find an argument or line of reasoning I hadn't seen before, even if it is one I don't agree with or could poke holes in, I feel like I gained a little bit of value. I think an important distinction to make is the difference between comments and discussion. Commentary implies a kind of one-way offering of one's opinions (obviously attractive to many people) whereas a discussion requires that and more. The person offering his or her opinions has to be open a critique of their own ideas; as much as you may want to bring the other person to your side, so-to-speak, you also have to be willing to let them bring you to their side. It's hard, and more rare, because both parties have to make that effort. It's much easier to just give your opinion and check-out, mentally speaking.
No, because this is a contradiction. Twitter by its nature is a set of comments. If I obey the Twedict, then I have already read an internet comment and failed its instruction. Any other comments I read would merely compound the sin. I'm not a fan of random dictators, so I shall not be down with this clown. Nevertheless, I keep a certain limit to my comment consumption over the work day. If I've spent too long reading comments (especially on Fark), I realize I'm avoiding work and got scared of being productive.
I read them on Hubski and lobste.rs. I read them on the math, CS, programming, and music subreddits I read, but usually not in other subreddits. I don't usually read them anywhere else. The places where I read the comments tend to have good comments, the places where I don't... don't.
That's rarely true for the vast majority of the internet, or if it is, it's buried fucking deep down in there. Reddit can sometimes make the exception, same with Hubski. From my purely subjective experience - which is the best I can offer - comments on sites that AREN'T heavy on the comment sections (i.e. article comments, youtube comments) are usually a lengthy, cliche libertarian follow up to something by and large unrelated, blatant racism, or just "wow I totally get that joke! lol" I tend to avoid the comments. I'm not these people's friends. I don't give a hot fuck what they think about the issue at hand or their opinion on anything from what I'm wearing to the latest political turmoil in the Middle East. Do what people should have been doing this whole time; read the article and think about it critically on your own. Also be sure to follow this maxim when reading about any advance in technology; if it seems too good to be true, it probably is.
Depends on the culture of the place. My two favorite non-Hubski websites are NYT and Ribbonfarm. There, the readership is such that the comments are usually of pretty high integrity. I don't like that NYT doesn't allow for discussions, although I've read that they are working with the MacArthur Foundation to create a commenting platform that they say will totally change the way commenting on newspapers works. I'm interested to see it, and hopeful that we can apply some of their concepts here, if they're decent. It's amazing how bad other supposedly high brow news sites' comment sections are (e.g. NPR, Washington Post, Economist). It leaves one with the impression that many of the commenters probably aren't intelligent enough to digest what it is they've just read. The only website I actually comment on is self-evident from this comment.
I have a browser extension that blocks comments on every site that has them. I highly recommend it. The kinda stuff I read has no "discussion" of value and more often than not just leaves me feeling bad for the rest of the day. I try to remind myself that they're just Internet people and probably a minority in the grand scheme but that doesn't really help me a whole lot because, well, they're still people. A non-zero amount of actual, real human beings exist with attitudes like you see in comment sections and that scares me. So, out of sight, out of mind. Here's a very good transcript from a show that talked about something like this recently.
Part of that's not just what you're looking at, it's who you are....a lot of times when people say "The Internet's terrible" or "The Internet's wonderful" what they mean is their Internet is terrible, their Internet is wonderful. The things that they choose to expose themselves to are good or bad.
edit i said a mean thing im going to take it back :'(
I do normally, sometimes they are horrible sometimes they are incredibly insightful. Mixed bag really.