Depends what you're doing, M1 Max is around a minute for 1 SDXL image and the machine feels like it's choking while it does it while a 3090 will do it in 9 seconds and doesn't feel like it's breaking a sweat.
Im more thinking about the training side because it could be compelling to buy a beefily specced m3 max if it can replace what a dedicated gpu rig could do and also be a daily driver.
Llama definite a bit of a different story though.