It's funny, when I first heard of Nick and Carla happening, I was dreading it- I didn't see how they fit and another one who was involved with Leanne, really? But they have quite a natural onscreen chemistry and I actually quite enjoy watching them together. Not sure if I'd want them properly together (especially since Carla's leaving) but I quite like their friendship-on-the-verge-of-more deal at the moment.
Nick and Erica are fine, but don't really have any particular opinion on them.