If it seems that way it's because "smooth mode" is enabled, which was introduced in the Saturn version. It's also present in the 3DS release, developed by M2, who also converted the game for Yakuza 0. All smooth mode does is make the backgrounds run in 60fps, it does not change the game speed at all. If you compare the Yakuza 0 conversion with the arcade pcb you'll see they run at the same speed.
Thanks for that.
Must just be my hazy memory!
Still can't believe I used to play such a low fidelity game on a huge arcade machine screen with a hydraulic plastic Ferrari attached to it!