I'm loving Diablo 3 right now, been playing it for many weeks. But I only puchased it long after they fixed all the problems.
Right now it's a solid game, but I understand it took a very long time to get to this point.
You can read about some of that process to fix Diablo 3 here.... Well recommended reading...
https://www.kotaku.com.au/2017/08/how-blizzard-saved-diablo-3-from-disaster/
Diablo 2 will be very difficult to repeat and get right. And the above article mentions why, it may be impossible to reproduce the exact elements that went into Diablo 2.
My only criticism of games like this is the grind to get the best gear. But I suppose that's part of the attraction.
If you bought Diablo 3 and were disappointed, I challenge you to reinstall it now and see how they have fixed it.
It's still not Diablo 2, but it's not far off.