I've had as many varied experiences as I have with clients who'd not declared they have any sort of issues.
One man was a real nightmare, who would these days be eliminated by my screening - at the time I was vulnerable with my own issues, and I gave him a lot of leeway. He caused me a lot of trouble, no least so when his supposed 'carer' threatened to report me to the police

. I had kept all the demanding 'I want sex' emails and texts from the young client (he was over 16!).
Interesting when a few years later that carer (who I was able to link to a caring 'organisation'), contacted me asking for a booking. Errr, very strange and no thank you.
Others have ranged from nothing noticeable, to some who need extra time at the end just to get their bearings and arrange their transport home before leaving.
Some of the worst problems have been with men who I would say have 'attachment' issues, have no empathy for others - which are supposedly Aspergers/Austistic traits (sorry if I get any of this wrong, I tend to see people as people rather than get hung up in diagnosis) who if you suggested they fell into that box would not accept it at all. They also tend to be people who have to remind you how 'nice' they are. In my experience is someone is having to say that they are 'nice', they are almost always very difficult to be with and struggle with relationships throughout their lives.