Lore and theme-wise Quinn is somewhat boring.
Her gameplay identity is fine ever since the marksman class update, she fills a unique ( albeit somewhat annoying ) niche by being a splitpushing roaming toplane marksman. When it comes to lore and model design though . . . she's just really unappealing. She's got not a lot going for her in her lore except for a dead brother, being demacian and valor. Reading her lore also made me somewhat uncomfortable because she somehow tried to deal with the loss of her brother by turning a bird of all things into a "new" Valor, similar to how that one professor turned a robot into a second Orianna in her old lore, which of course makes Quinn somewhat unsympathetic.
When it comes to looks, she's just very far below the standards of most other champions.
http://ddragon.leagueoflegends.com/cdn/img/champion/splash/Quinn_0.jpg
Other champions have very unique and awesome companions that you can't find anywhere outside of league. Annie has a teddy bear that she can turn into a magical firey grizzly, Skaarl is an aweome mix between a lizard, an ostrich and a retard. Even Beatrice is more intriguing than Valor, she is really creepy and has that 6 eye thing going for her. Valor though . . . he's a burd. That's it.
They took that theme even further and thought like "since she has a burd as a companion, let's make everything else about her a burd" so literally every piece of equipment is aimed to look like one and in the end it not only looks completely impractical but also stupid. Her helmet, her crossbow that looks like a children's toy and especially her really weird looking wing-cape make her look like one of those discount Marvel or DC superheroes that people only really know because their outfits and superpowers are hilariously dumb.
I don't know . . . there are a lot of champions in the game with a really good lore but horrible kit and model that needs to be updated but Quinn is pretty much the only one where it is the other way around. Her kit is great but her lore and model are just way below what Riot's standard usually is. I hope something gets done about her when the Demacia event hits in probably a few years or so.