> The slow tempo loses you mental oversight of what you are trying to play.

When I was a drummer, I used to think that too, but it turned out to be false most of the time. If I really wanted to make something sound good in a fast tempo, I had to make it sound perfect in a slower tempo.

My teacher used to say "if you can play it fast, make sure you can also play it slow"

But, as always, it depends.