Yes, I expect an ARM MacBook Pro not to be that massively faster in the peak pearformance, but it should run considerably cooler. This means sustained peak performance and overall less fan noise. If I have anything to critisize about the MB Pro, it is that there is just too much fan noise with even not so big loads and the machine just getting very hot. Adding more battery lifetime would also be a welcome improvement.
(Though, 8 high performance cores would also deliver a quite impressive speed)
I've had problems with MB Pros getting too hot for at least a decade. My 2008 model was actually too hot to use on my lap. Sun-burn level of hot if I wore shorts, or even something like pajama pants.
This is kind of what I expect of the 16" MBP and the higher end 13" MBP, cooler running with low/ no fan noise, tremendous battery life, 20-50% better performance than the M1, drop 8GB RAM and offer 32GB, better video performance (support dual 5k displays).
It's possible they will launch the iMac with the same chip as the MBP 16 as well.
