Lightbox has reduced their price from $15 per month to $12.99 in reply to Netflix starting in New Zealand. This matches Netflix's Standard Plan price.
Lightbox has more New Zealand content however Netflix has a much bigger catalogue especially when you switch regions. Of course, you can get 12 months of Lightbox for free when you sign up to a Spark broadband.
Try them both out and see what works with you. Competition is great!