I gave it a try this week and am obsessed with it. It is a true and worthy sequel to the Diablo franchise.
It is FREE to download and play
they make their money off micro-transaction, NON-pay to win ones, things like cosmetic effects, etc.
The company is awesome, their developers respond and interact with the forums constantly, they are patching things every week or so and embrace community feedback.
It is one of the most complex and in depth ARPG's you'll ever play, ever system has a ton of customization and complexity.
Please download it and give it a try for a few days, I guarantee you that you will be instantly hooked. The controls will feel slightly stiff at first coming from D3, but it's not that bad, you get used to it. Outside of that, you will find these brash young upstarts at GGG totally pwned Blizzard at their own game.