Proper performance benchmarks are already out there and exactly as you’d expect per core count and device size:
CPU performance is identical to the relevant Pro (because they’re the same in terms of CPU) and GPU scales basically linearly with core count so the 40 core Max has pretty much double the performance of the 20 core Pro for GPU intensive tasks
The reason the Pro is getting all of the reviews is because it’s the biggest improvement over the hobbled M3 Pro