If you are playing with a small edge then the faster you go the higher the win rate. That is not important at all to recreational players nor is it important to anyone playing a negative game. I could play FPDW at about 1200 HPH but could only maintain it for an hour maybe two. Since the game is boring to me I couldn't play any longer at any speed.

The game I currently play is old, old, old (still coin based machines). Can't really hit 600 HPH unless I'm losing badly. Hence, I don't even try to play fast although I will play 2 machines at once occasionally just to keep in training. When I do that I can get to around 1000 HPH.

Yes, there are people who can play around 1600-2000 HPH playing 2 machines and still maintain high accuracy (not me).