As for unique dialogue lines for individual villagers, I don't think there was much, but in WW I know Gwen gave me a line about how hard it was for her to be a bird who can't fly (I'd guess Friga would give the same line) and Marina wondered if her seafood diet was strange considering how she is seafood. I thought those were cool but they're the only ones I know of.
I'm not sure how the amount of dialogue compares either, but while repetition tends to be brought up as a common complaint, my problem is less with that (because every game's dialogue can get repetitive) and more with the content and quality. For example, in NH, I personally feel like the dialogue lacks variety - lazies only talk about being disgusting, smelling things, and bugs, jocks only ever talk about muscles/working out, and peppies only talk about being pop stars, and all the lines have the same kind of feel. WW villagers also had a focus on certain topics (NH jocks are pretty similar to WW jocks, except nicer) but they seemed to have a wider range of feelings (lazies would get livid because another villager insulted them or disgusted when they discover a horrifying food combination, peppies would get depressed because they accidentally said they wanted to eat a pastry chef and scoff at another villager's new mop, jocks would get confused by other villagers' relationships and angry when they thought you blew off their training regimen, etc.). NH may have a lot of dialogue, but it all feels the same and so it doesn't seem like there's a lot there (at least to me). The villagers bring up so much contextual dialogue/short small talk lines which we tend to see pretty much daily that it gets old fast, and it reduces the amount of the more interesting dialogue that you'll see from them. I don't know how the dialogue trees in WW work, but in my experience, villagers didn't keep bringing up the same few lines of dialogue the first time I talked to them in a day; they seemed to go right for the fun dialogue.
Not counting the contextual dialogue, the more common dialogue I come across involves personality quizzes ("you chose chai tea, so that means that you need to relax or whatever", etc), instant-bestie stuff ("I'm so glad we're friends!/talk to me if you need someone!/your muscles look great!" even if they just moved in a few days ago), or preachy stuff ("be yourself!/never give up!"), which gets boring for me fast. On top of that, villagers always agree with you if they ask for your preference on something (ex. sunny days vs rainy days - peppies will always agree with your answer), and they love every gift they receive from you or another villager, whereas in games like WW, normals will ask you if you eat your favourite food first or last, where they'll tell you they always eat it last regardless of your response, and villagers have disliked themes and will definitely express their distaste for a gift if you deliver something they don't like, which makes them seem more like their own person and less like someone who's only there to serve and agree with you.
While I do like the meaner dialogue (WW at least, as I've never played GC) I don't mind the nicer personalities (except in the snooty/cranky cases where I think they should at least not be instant friends with you when they move in), but I think when you try to make everyone nice, you run the risk of them being boring - not that nice is inherently boring, but it tends to result in less conflict: the way NH did it, everyone wants to be your friend right away, everyone agrees with you, everyone thinks everyone else has great taste and is totally awesome in every way possible, and everyone is happy-go-lucky all the time. For some people, this makes for a happy and peaceful game which is great, but others (like myself) wouldn't mind some spice, sass, and drama to make things more interesting and lively! WW's mean dialogue also often came across as more humourous than hurtful ("Don't you know how to knock? Were you raised in a barn?"/"You're so stuffy! You're like my grandma's basement!"), which I think makes it more enjoyable and hopefully wouldn't be taken too seriously.
I've mentioned villagers being instant friends a few times, so to compare that with WW, I got dialogue from Coco once in WW where she said she wished me and her could be better friends, like she and Blaire were (this was a few days or so after she moved in - and reminds me that villagers also had relationships with other villagers in WW, and would sometimes ask you how well you thought they got along with other villagers and they'd tell you if you were right or wrong (not all of them get along!), and some villagers would gossip about other villagers). This indicated that we weren't close friends yet, but maybe we can build something! After talking to her more and building our friendship, she gave me her picture, my birthday cake, and told me I was her dearest friend (although Blaire was gone by then :P). Seeing our friendship progress like that felt so rewarding and I loved that! On the other hand, all my normals in NH treat me the same when they move in as they do after they give me their pictures, and my relationships with them feel so static. I don't care about most of my villagers because even though additional dialogue is apparently unlocked as you increase your friendship, I don't notice any difference in how much they like me or how they treat me because they all love me from the day they move in.
Not sure if this is what you were looking for, but hope these comparisons help give more of an idea of what WW was like!
