PvZ Heroes Review

CONS

Buggy client (though improving with each release)
There is nothing worse than being about to win a game and then getting a message that says “there is something wrong with your game”. When the game released, this was a fairly common occurrence but PopCap has been very good about releasing periodic updates and with each one the game gets more and more stable. There are still a few hitches here and there though but I think it is reasonable to expect the game to be very stable going forward.

Questionable client-authoritative functionality that allows for hacks and abuses

There have been reports of people causing problems with the client.

Long animations make it harder for new players. 
The one other outstanding gripe I have with the game is that the animations for the characters, as enjoyable as they are, reduce the time you have to make a decision. Given that this time is fairly short in order to ensure the total game time is short, this can often interfere with the game and give you a loss when you should have one, specially when learning the game.

So there you have it. I think the pros far outweighs the cons and it is clear that the developers are giving this game a lot of love so you can expect features and improvements to happen consistently as time goes by. If I had to chose a single CCG to focus on and my base device for playing was a mobile phone it would definitely be this one.