Tried it out the first week of beta, and it had a lot of bugs. Like I'd get to the second act in hardcore, and monsters would randomly one shot. But when I got there with other characters they'd hit like a wet noodle. And it happened a few times and generally drew me away from the game.

Have they fixed a lot of these things?

As well as the server crashes/lag?

It has improved a lot, but i never got 1 shot in closed beta even except by vaal.

It was the second act. Forgot what dungeon it was in. Spiders and electricity. Happened to me once there, and somewhere else further on. But other times same spot I could pull half the dungeon and they'd tickle.