I've not skied either ski, but a little reseach indicates that the SX7 is the lowest level ski in a high performance line. The Balanze 3.1 is basically an entry level women's ski. Suitable for a person who is relatively new to the sport.
With that said the SX7 is the better ski, but not for a beginner. If the skier in question is an intermediate level skier the SX7 is definitly the better choice.
well she is a beginner but wants a ski that will suit her for a few years. so she might want to spring for the sx7. Her form is ridiculously way ahead of her skill level so it will probably be up to her on which pair to get. Thanks alot guys. I really appreciate it.