I think it depends on what you intend to use it for. XA10 has 64gb internal memory plus 2 sd card slots which makes it safer cause your data is stored in 3 places which "hot-switches" between each so that you dont miss an important part in the event. It also has a LANC input which is valuable. Based on this oversimplification, I'll say, this is for events like weddings. NX70 on the other hand is 94GB internal memory plus 1 sd card slot. Rain and dust proof(except for it's xlr handle). It also can store straight to an external HDD instead of through a computer which saves alot of time. Not forgetting that it can shoot in complete darkness with it's "nightshot" infrared. I think this is more for documentary filmmakers.
I haven read substantially enough. but will let you know more in my next comprehensive reply to this post;D