My PC just finished the update to v1903 this morning, and so far, I’m happy with the results. The lag in explorer has cleared up, things are more responsive, and CPU usage has dropped considerably with many of the processes. My fans no longer sound like airplane engines every half hour or so, as windows does whatever crap it does behind the scenes.
It’s too early to say 1903 didn’t introduce new, shittier bugs, but so far, it really appears to have cleaned up issues on my system, without breaking anything else. For a rare change, it seems like MS did good with this patch. The next one, in six months, will probably destroy everything...