Are Huangshan and Zhanjiajie Scenic Area similar to eachother?

Hello everyone!

Me and my girlfriend are planning to visit China for 3 weeks in July 2015. This is our second time visiting this beautiful country.

We plan on seeing both yellow mountain AND Zhanjiajie. I was just wondering if they are not too similar to each other. From the pictures I can see on Google Images they kind of look alike. Since it's not very easy to get there and it's pretty expensive, I was wondering if doing both could be a little pointless and if it isn't better for us to visit just one and use the extra time to visit some other cool places.

Many thanks for helping me out witch this, I've been searching for other threads that answer this question, but I haven't had any luck so far.

Take care, and a happy New Year everyone :)

Timo