My experience of Keto took place over six months earlier this year. I have never been a believer in low fat so a high-fat diet seemed perfect for me. I grew up in the 50's and 60's so fat was normal in the diet and we were not overweight at all. I think at school I knew two people over-weight.

On the positive side, I lost a lot of weight over the first 3 months, I had loads of energy so it was great. My wife had the same results.

Over the last three months of the keto diet, the weight loss slowed to about same as a normal diet of around two pounds a week (1 KG)

On the negative side, I was really bored with the food and my wife got diverticulitis really badly. Fortunately, she responded to antibiotics (three types four times a day intravenously.)
It seems the very high fat stresses the bowl and the seeds used as snacks almost finished her off. Of course, you have to have a few diverticles to get diverticulitis, but most of us don't know until we get a problem.

So for me except for the boring diet I got on with it well. My wife almost died and was 24 hours away from major surgery when the antibiotics finally worked.

For us, we prefer to not bother with keto anymore.