I tried it. I didn't play many games like this so far, so I can't tell how good it is compared to other 'trading card games'. I only stopped playing it because it needed too much time, so that I didn't have enough time to play this while still playing DDO.
So I never became very good in this games but it was fun and balancing seemed to be ok. One of the four 'factions' seems to be stronger and easier for beginners, but as far as I remember there were videos or guides around how to beat specific 'faction decks'.
And apart from the price for the game you can also spend real life money to buy new cards in the card store. But this isn't pay to win, just a bit easier and faster to get some rare cards but you don't need these cards to win and they don't make winning much easiert.
On the other hand... as far as I know you buy the game now and get all future updates for free, like with Minecraft. So I think you are going to get very much for your money.
But yeah... if you are slow thinking and or have an opponent with the same 'problem' a match can take a while, unless one of the players is using the deck/faction for an agressive start. Countering such a deck is probably hard when beginning with the game but it isn't impossible. And there are also some challenges where you can try out your deck and earn first ingame cash to buy new cards if you want to do so before facing other players.
And I never had lag problems with this game.

Would say if you like trading card games it's worth to try it, doesn't cost that much money.