I have M1 Max, 64GB RAM, 24 core GPU and 2TB SSD. I have specific experience as I am a professional photographer and I went to the trouble of trying out the applications that mean the most on 16-core and 24-core GPU configs. That means Adobe Lightroom and Topaz Sharpen AI. Lightroom improves only slightly with the 24-core, except for an operation that I do fairly often, which is to generate hundreds of JPGs from edited raw files. In that single operation, the GPU scales almost perfectly, with the 24-core being about 45% faster than the 16-core. For Topaz Sharpen AI, the 24-core is even better than that, for some mysterious reason. I carefully benchmarked a batch of 45mp raw files being sharpened with the 16- and 24-core and the bigger config is about 60% faster. I can't explain that easily, although it must have something to do with the code in Topaz. At any rate, those are the two apps whose performance I care about, and the 24-core is clearly of value in them.
I didn't compare battery life on the 16-core version (I didn't have it for very long). I purchased the 24-core version and I find that its battery life isn't what I hoped, although it sure obliterates my previous Intel-based i7 MBP. I would never dare downloading 2000 files at a media center, sort and select them with PhotoMechanic and then try to edit a few hundred with the i7 machine unless I had AC power. It just wouldn't get there, not even close. With the M1 Max, I can do it and get the whole thing done if I need to - but it will go back in the bag with maybe 10-20% battery remaining, after only a couple of hours of intense work. From the early reporting I was hoping to do that same sort of thing and stay above 50%, but sadly that is far from the case. As I said, my previous Intel-based MBP would only make it a third to a quarter of the way before running out of juice, so this is far better, but still not up to the projections.