The only problem with K (for me) is that my brain always thinks it'll be awesome to do it when I get drunk. Before I get drunk, I think, "No K tonight, can't handle the hangover," and then I get drunk and inevitably it's, "Hey, taking some K right now would be an awesome idea!" Worst hangovers I've ever had have been from combining k and alcohol, even at low doses of each. Dehydration sickness. It's usually a good time for an hour or two, but nothing useful comes of it, and I usually have almost no memory of the experience.
That's the reason K is best in combo with a serotonergic psychedelic, I can retain the experience much better. One of my most profound and euphoric tripping moments came on a combo of mushrooms and ketamine, while peaking on both, listening to Israel Kamakawiwoʻole's "Somewhere over the Rainbow," and I remember it very much more vividly than anything I've ever done on K alone. It also can lower paranoia while allowing really deep trips because you can take a lower dose of the psychedelic and then "dip" deeper into the rabbit hole with the K, while knowing that if the effects are overwhelming they'll be stabilized within the hour. Really interesting audio distortions from that combination.