thinking of watching this but is it as good as the original goong or is it just a knock-off??

no its not as good as the original, but it is a nice drama.
but its too early to completely judge.
I personally love it more than the original becuase the main leads have really good chemistry and the main male lead isn't as frigid. 
For me, the original show had more depth.  The relationships with her friends and family
were better thought out and a large part of the show was the princess struggling to become a royal which made me like her more.  I see the Thai version of this show focusing heavily on how cold the prince is and her unhappiness in being married to him, which would be ok if it I didn’t keep comparing it to the original.  What keeps me coming back to the Thai version is the chemistry between the main two characters.  This show has made my heart flutter once or twice and I hope it will again once they both start realizing their feelings.  I also hope that they do a better job with the ending.  The Korean version felt very rushed.  I just wanted more of the lead characters being happy together after so much struggle.
Original Goong – basically because I don't like the cast in this Thai version. I'm Thai. This show is actually not that popular in my country. I'm also so tired of Thai people liking mixed-ethnicity actors. I don't see their charm. Plus, Ungsumalynn really can't act. The only good thing about this is that it's produced by a cable network, so the budget is higher than normal dramas and so the cinematography is way better than usual Thai lakorns.
the original. full stop. 
tho the leads of the original has less experience that the leads in this adaptation when they made the drama, it's point on acting. you just can't compare the two except for the storyline.
The original is better all around. This one is so irritating that I have given up on it after 14 episodes. The script and poor acting make it hard to watch.
There is no comparison between this and the original...this Thai version doesn't qualify to be compared......I really wonder if ppl of Thailand r  liking this??
Goong all the way please.
If anyone's curious about my view or Thai people's view on mixed ethnicity actors and actresses: http://mydramalist.com/discussions/thai-actors-act...

This one,without a doubt. I REALLY LOVE Inn and Khaning. I remember being turned off of Prince Shin long ago, and complaining SK Goong is draggy, while this one, even at 20 episodes, made me feel wanting more (bcos I love the main couple). Better ending (but could have been a better ending). I felt so heartbroken when I finished it cos it meant I'm not gonna fall asleep with a smiling heart and face anymore! 

The original.

I almost flip my table when I saw they are faking the kiss

The original one. Goong has more depth overall. Thai version can't even be compared with the original. I couldn't even finish this one.

There's no comparison. "Goong" in its original version, period.