i guess the most obvious thing about 6's is their anxiety. it's there, it's happening, it powers basically everything they do whether overtly or covertly. i know some people who are obvious 6's, some close friends and relatives, and it looks like to me that they can have lots of really nice stuff, put on a great presentation (OR NOT--just the ones that could be mistaken for 3's), and they genuinely want to share it with others, because they want others to like them, because they need that security. 3's are more "no! mine!" a little bit reserved in that way, they have a more "look but don't touch," vibe, like a distance because they want you to believe in them, and aspire to be like them, but they don't really want to be your buddy.
6's are more scattered, esp if they have that 7 wing, their thoughts are scattered. they know their emotions, but their heads make a mess of it, so it's tough to get them to decide or sort of "pull it together" to make a decision. 3's are much more focused, their aim is hiding their emotional issues, which is easier since emotions are more internal than thought (IMO, feel free to disagree), so they appear more controlled, focused, and somehow icy (reserved), because if they're dealing with issues, it's on the inside, where people can't see it.
6's (and my brother is a classic 6, he's always talking through his decisions with me and trying to figure out what he should do about things) are all over the place. they are less concerned with how they appear to people (which is why you have some pretty crazy, reactive sixes and why that can be confused with over-emotional fours) than figuring out this crazy swirling of thoughts in their head. that's why you can have a 6 that will vent forever, and they are usually unapologetic about their own emotions, they know how they're feeling. 3's are generally less likely to vent, and theyll probably not really talk about how they're feeling because 1. they don't know themselves, they're trying to repress it 2. they wouldn't let their image be tarnished, unless they're pretty healthy, or you're pretty close with them. also, look at how they get unhealthy. 3's will work to maintain that veneer even as the base is crumbling; 6's will abandon all sense of veneer and just be extremely paranoid. they're not concerned with image.
the problem i have with celebrity typing is just that celebrities are so exaggerated, like no one really acts that way in the real daily life business, that it's hard to say "OMG i am exactly like madonna! or lady gaga!" they're public, but they're caricatures.
as for myself (because all this is is really getting to my own personal type...narcissistic much?

i know im not security-obsessed. im not that anxious (although i can get a bit anxious, esp in social situations where i think i misspoke, but i get over it pretty quickly), but i do value security in relationships and im super indecisive, mainly cuz i don't want to deal with the responsibility of other people hating me, or making a wrong decision. i don't try to figure out the worst-case scenarios of every situation. and im not really rebellious. however, i do have and strive to have close friends--or a close group of friends.
i guess when i was younger i was obsessed with making my way to the top, very ambitious. i got burned out in high school, and now im recovering momentum and going full-speed, but im not what you'd call ambitious. i care a lot about looks, but im still relatively chilled about it compared to a lot of people i know. i have that drive, but i want to be normal. i mold myself and contour myself to be what others consider successful, whether that means super laid back, super smart, super driven/ambitious, etc. sometimes i feel like i don't have a personality myself because im always gauging the enviroment (and i've bounced around between a lot of different types of enviorments) and trying to fit myself into their ideal. im also not super assertive or confident, but im verryy self-absorbed LOL. and im not a follower. im not a leader, but i hate feeling trapped, so i like doin my own thing. i know on the outside im more reserved, im very careful about how i portray myself to the world, im more controlled, which is why when i misstep (like misspeak or say something overkill), it's a major deal for me because how people view me, is extremely important to me.
and in general, in terms of 3's, i don't get where they fall in with their TRIAD. i mean 2's and 4's???!! (i've thought i was both. for a very long time, i was convinced i was a 4--i really think im a heart--problems and emotions is where im at, not such a "head" person). what if their wings influence them a lot? or not at all? i mean, that's a very different type of person. and the fact that they're the centers of their triad, the typifiers of their triad, cracks me up. and confuses me.
anyway, that was a lot, but if anyone has more insights/comments, i'd love to hear them.