While I can't say Steins;Gate 0 was awful, it did NOT live up to its prequel. At all. But there's a genuine reason for this. Steins;Gate 0's curse was was none other than being a frankenstein's monster amalgam of a storyline.
I believe the nail in Steins;Gate 0's coffin was the nature of the visual novel it adapted. For insight, the original Steins;Gate visual novel had a linear main storyline. The other routes outside of the main storyline were not necessary to enjoy and understand the story, and were more or less just extras focused on a specific character. Hence why the Steins;Gate anime thrived so well as an adaptation, despite only adapting the main route; the other stuff wasn't even plot important. In stark contrast, Steins;Gate 0's VN had DRASTIC plot divergences from route to route, and reading each route was ENTIRELY necessary to enjoy the full story.
With six extremely different stories to adapt, each going hand in hand, it's no wonder the anime suffered like it did. Several elements are glossed over and/or left unexplained. But perhaps the most major flaw, getting a proper grasp of the new antagonists simply just wasn't possible in 0's anime. In fact, one major villain of the VN's entire existence is left ambiguous until they're killed off.
There are a few positive elements, though. For one, while Steins;Gate 0 was by no means an amazing adaptation, it didn't suffer NEARLY as bad as Steins;Gate's lesser known big sister Chaos;Head's anime.
So, the verdict? It's watchable. If you liked the original, go ahead and give 0 a try, but don't raise your expectations too high. You're better off waiting for a Steam sale (or whatever platform you prefer), and snagging the visual novel for the proper story.