I personally become frustrated when a visitor is leading the Davening and is slow like it is Yom Tov. If they’re fast I’m ok since I can linger on my own.
I think the sages would support the statement that the Davening should proceed at the normal rate for that specific shul.
A related issue is when a visitor uses different tunes than the shul usually does. I respect the visitor who checks with the Rabbi to learn the customs prior to leading.