If you listen to someone who's living is derived from "brand X's" sales (or they wish it was), you can easily recognize it. GraemeF is good example of someone who will tell you everyone else sucks, but my stuff is the best. If you take advice about gear on this forum, don't take it from someone who is affiliated with a particular brand and holds this attitude.
Honest reps of a particular brand will tell you about the shortcomings of a particular model that they sell. Extremely honest reps will even recommend another brand if they do not feel your needs are met by that brands offerings. But that would be like finding a unicorn. And this advice really only applies to someone who has already developed their style on different kites.
What the honest posters here are telling you is that going for one of the overpriced brands is not going to make you a better kiter.
My advice to is:
As you are just hitting your intermediate stages in kiting, maybe go for what the good AND friendly kiters at your local spots are using. This can make it easier for them to give you advice on how to execute tricks as they will have near identical gear. If that means paying a little more, and you can afford it, do it.
If there are lots of different makes and models of kites at your local beach, make a careful choice. Only dump lots of money into a premium brand if it helps you feel better about yourself. That is a pretty lame reason, but it can have a real psychological effect on you and possibly even improve your riding. If you feel good about having really expensive stuff, at least you are feeling good about something.
The biggest considerations for you should be:
1. Availability - GraemeF has previously stated that Core is not always available as their business model is to under-supply the market to keep prices up.
2. Suitability - If you are leaning toward wave, go with a kite with at least some wave capabilities, same for freestyle, or wakestyle.
3. Track Record/warranty - Have the previous years models had issues? or is the company known for giving riders the cold shoulder on warranty claims?