They really have radically improved the situation for prefill speed! But the generation speed is behind enough that you'd notice. An M4 Max is a great choice I think.
Ah, my bad. I got those confused. Yeah, from M1 Max to M4 Max has been noticeable, but M5 seemed to improve even more in a single generation beyond M3 to M4. In any case, having 128GB of memory (before memory prices went up!) was a great choice.