Generally, I've always tended to prefer the more understated performers. Rachel and Kara were among my favourites for that very reason. I can see Sophie's not quite up to their level yet technically, but I do like her style. And I do get the impression that she's enjoying every second of the Strictly experience, only she just doesn't 'gush' about it (I put gush in inverted commas because I don't always mind gushy contestants either - it's not necessarily a bad thing, it's just not Sophie's thing).
I'd also say Sophie and Brendan (along with Mark & Iveta) are the ones I enjoy listening to most on It Takes Two. Their interviews are laid back but still engaging and you can tell there's chemistry there without them feeling a need to try really hard to show it.
Oh and I love Sophie's dirty laugh