Ever wondered what catgirls would look like in real life? wonder no further... these have got to be the most creepily cute photomorphs I've ever seen...
Which of course just begs the question... are cat ears really the first catlike quality you'd develop if you were slowly transforming into a cat? I mean... 5% BAM! EARS!
I would choose:
Muscle type (cat muscles are 10x stronger per volume)
agility
senses
appearance