I finally ended up trying it a week ago, I wasn't interested at first but after seeing so many people playing it, I got curious because it looked fun. However in my case it didn't get me hooked, I opened a couple of packs and it was ok, but the gameplay seems a bit boring to me. Plus I have the slight feeling that when the new card packs/new collections arrive, the difference between the free player and the paying player will be bigger.