Like with everything, it depends on the artist.

I find that the less experienced ones are likely to be more stress inducing clients, because they often don't know what they want, what to listen for and they are superfocused on irrelevant details.

Oddly I never had a case of someone being difficult to work with because of their legacy stuff.

But then again I didn't produce that many albums and rather pivoted to mixing/mastering and lately to game sound design. I found that the music budgets are way too small for how slow I'm when dealing with it. And people often expect you to work infinite hours on their stuff as well.

I also know there are producers that can do what takes me months in a very reasonable time. So this is most probably just me not being good enough and compensating for it with time.