Why? Are you compiling opinions for some research or something? Regardless,
cons: I've always liked how they think they know everything via coming to a certain conclusion or making a statement that seems directed toward you in which it is easily seen how they came to said conclusion, but in situations where there's a certain piece of information it seems unlikely for them to have access to which would lead to said erroneous conclusion.. There might not be any non weird ways to convey that info to them so one is left to wonder if they'll ever consider the possibility and if so how much of an effect it would have on their m.o.. Seems to be more of a special scenario.
I may have met one that was planning on killing his mom, and when probed deeper, it was because she supposedly wouldn't give him his video games. He had a crossbow and everything. When asked what games he couldn't get back, it was like, "Halo 3, Ace Combat 4, um.. That one game..." and there seemed to be about 7-10 total. After realizing how ridiculous the whole thing was it was then laughed off as, "Never mess with an angry gamer! Yeah!" then the whole mood shifted to that. Never met him again so not sure how long that lasted, and he could have not even intj in the first place of course. When he pulled up in the car with the crossbow it turned out he also stole a laptop out of his mom's car because the window was down. He said, "Who leaves a laptop in the backseat with the window rolled down? You're just asking for it to be taken.. Who does that? You have to have less than two brain cells to do that..."
After he said I almost immediately considered the perhaps slight possibility that she could have done that on purpose for bait, then again I don't know all the detail of the situation so it's possible she couldn't have been expecting him to visit and set up a trap, depending on how spiteful she is and the veracity of their feud. Also, there was a dude who seemed to be enfp there and it seemed as if he sort of considered the same thing.. We both didn't say anything out after he said that but I think I noticed him thinking about something, and then the "intj" dude seemed to notice something about our lack of response then the topic more or less changed. Also, the "enfp" dude could have just been stoned and been thinking about something else the whole time.
Also, I'd suppose I feel remotely bad for the stereotypical lack of socialization that's apparently documented. I'd consider it a con because I would just feel bad for them for some reason. I mean, I also have issues working with people but it seems kind of different from the intj approach, not to compare myself or anything. If I say anything more it'll be too easy for someone to have a certain idea about what was said, and if they publicly say anything it'll be too easy for me to say, "But, no, because...." for however long that can last with however much material is available, pointing out any semi arbitrary, on one side at least, slight differences between two or more models, in other words, it might be becoming a different topic/conversation but if elaboration is requested further discussion may or may not be possible.
Pros: They can be pretty cool, I guess. For certain people, perhaps, good conversation can potentially be had due to their stereotypical interests, if any value is placed on the fact that some people had a "conversation".
"Did you see him?"
"Yeah"
"What was he doing?"
"Standing there.. Like he's better than everyone!"
He obviously heard that exchange and it seemed to make him happy. So, that type of interaction/communication is probably semi valuable, but you might have to be kind of careful. It's somewhat commendable if anything. Can be annoying when they get too hardcore with it, and spot on I might add. INFJ obviously probably do it too, particularly females maybe, um, perhaps not withstanding the "fact" that it's valued amongst a decent female demographic in at least the USA, Australia, and France, whether it be dominant or inferior... I guess. It can be good because it suggests a certain amount of awareness ("carpe diem"/"live in the moment" is lame; i've always favored referring to "it" as being aware - loosely related to whatever the hell it was that i was talking about) but again, can be annoying when they get too hardcore with it because in certain interactions it might be suggested that one party must be careful with their communication, maybe depending on how manipulative one is attempting to be, if they don't care then feel free to do or say whatever, which can really go either way as far as manipulation goes, because the other party can still be amused, but the worry would come from conveying a potentially arbitrary piece of information but the 'person who favors previously expressed idea' could be overly creative with the interpretation and conclude a certain thing which would basically then equal mind games, I guess.
So, as far as pros go, they're pretty cool and individualistic I suppose. I seem to be sort of put off by their work ethic, though.