I was actually thinking of starting a thread like this but you've saved me the trouble, so thanks.
As I said to you last night, I don't really like the idea of 3s. The prospect of integrating to 3 also seems quite distasteful to me because they're so frequently portrayed as shallow, disingenuous, and narcissistic. However, cultivating better self-worth and a genuine interest in achievement is probably very good advice for most 9s. I've enjoyed being integrated whenever I've been integrated. It's quite liberating.
I can't think of any 3s I'm personally close to. The closest I can think of is a college friend with a strong 3 fix but I'm not convinced its her primary type. I didn't find her presence empowering or anything. Mostly, I just felt sorry for her because she was struggling with so many expectations and wanted so many things without being sure if she wanted them. I don't know, getting to a place where you've accomplished and acquired all this stuff and still maybe feeling kinda hollow inside and like there's still something missing sounds awful. I feel a lot of sympathy for people in that place even though I dislike what they pursue.
I think I'd have a hard time getting myself to like a 3 at first but once I'd managed to do it, things would be smoother. In contrast, I find it easier to like 6s but the longterm relationship is much more bumpy because their anxiety rubs off on me and I find myself thinking the same way. I have actual experience with 6s though, and none with 3s.