I know what a twist serve is, having hit with ArtLarsen in 1976.
My lefty twist on duece court usually lands near the intersect, kicks out to the left so the returner has both feet beyond the doubles alley as he contacts the ball. Most opponent's just hit a topspin shot to my feet as I approach service line position, so I have to half or low volley it into the ad side court.
RollieZalameda, who beat PeanutLouie in SanFrancisco's high school tennis championships, had a great high twist serve. He was No.2 for MissionHigh, and ended up No.4 at CanadaCollege his freshman year. Pea WON the CanadianOpen the following year, so she was no slouch.