Yep, I don't think you can really tell how a partnership with another skater would have gone, because it depends so much on the chemistry they have, as well their compatibility as skaters.
Kristina might well have done great with Kieron, but equally it might have been a total disaster. Brianne and Kieron are great together, and they both seem to have brought out the best in each other, which has undoubtably helped them get as far as they have. In fact all the final 3 seem like good pairings on the whole (even if I do find the combination of Hayley and Dan a bit too much at times...)
The only partnership I can think of this year that looked really awkward, at least to start with, was Fred and Emily. Most of them seemed reasonably okay.
Alex and Brianne should both be really great to watch on tour, I think.