1903 is very buggy right now on my pc.One look at MS Communities reveals that there's far too much wrong.Some are blaming computer manufacturers but this is MSs fault for not testing and relying on insiders and the average user to test their product.
And it's running smooth as silk on the Toshiba laptop (c55t) and HP laptop (15-g035wm) it's installed on.
The key phrase in the above is "on my PC." I am not denying anyone's problems, they're real, but by all indications they are, as most problems generally are, idiosyncratic to the machine in question.
You cannot use MS Communities, or Bleeping Computer, or any similar site as a representative sample of anything. People turn to these venues when they're having issues, regardless of the point in time, but at this point in time there's a feature update coming out. Using help forums as a metric of "how most of the users" are doing is a recipe for forming false conclusions. My analogy is to pick your own car's brand, and start cruising the forums dedicated to that brand. From what you read there you'd conclude that there has never been a functioning automobile in existence, because that's where people go when they need to fix something, not to report that everything's just fine.
There are no widespread reports of major issues with the 1903 update in the tech press or the general press, and those are the first two places that major issues, or even persistent issues of a more minor nature, would be being reported.