I was on it for many years. I had 3 toxicities and after the 3rd came off it because it was getting harder to keep my levels reasonable (I'd be fine when I had my labs and then a few months later toxic).

But, and this is a big but, it was a really good med for me. We've really been finding that out during this episode from hell that has lasted for 11 months without a break longer than a day of slightly feeling better. I learned that it was what kept me from outright psychosis apparently and it seems that it made it easier to get things to level off.

I had issues on it (the toxicities obviously), some hand tremors controlled by propanolol for a while mainly b/c my assistants couldn't read my handwriting, a problem called diabetes insipidus where my kidneys didn't hold on to electrolytes so I needed a med to encourage that, but when I wasn't having toxicity issues it was really a good drug to me.

It's also neuroprotective so it's good to take it for that reason alone.

I took it without ADs for a while (maybe a year) and then with various ADs until 6 years ago when I went on an MAOI and finally had an AD that worked without dosage issues.

I can't scroll up to your post so I'm hoping I hit all your questions here. My memory isn't very good today.