I would want a gastro specialist to really go through the risks for my specific circumstances before I signed up for it.

The reason it can be so powerful are the same that can make it risky -- people have died from poop that contained bad infectious material that was not picked up in screening, but also it might result in a transplant of traits from donors (food preferences, susceptibility to mental health concerns, weight changes etc.). That said, I also have an illness for which I would try any reasonably achievable treatment, even if the possibility of cure was low, and I'd be willing to take on more risk.

I used to conceptualise FMT as a very broad spectrum pro-biotic, but probiotics typically just pass right on through. An FMT really is a total re-colonisation an important system we still barely understand.