I don't vote ringers, never have. If you want to vote for the best dancer on the show then that's completely understandable and your choice, but my personal choice is to vote for someone who has learned to dance, rather than a dancer who has learned a new style of dance (also entertaining, but I prefer to see it in a show of its own; So You Think You Can Dance).
Of course where you draw the line between a bit of stage school background and full-on dancing as part of your career is a fuzzy line. Personally I didn't vote Denise, Kimberley, Rachel or Emma. I think I'm not alone in that, and that's partly the explanation for the perceived "anti-female bias" - far more of the good women have dance training - the only man who I can bring to mind was Tom.