I tried a day of the 15 Pro Max and gave up. My 12 Pro (regular size) with a case on is about the same size and weight as a Pro Max phone without a case, but for some reason, the usability of the 15 Pro Max with one hand was slightly uncomfortable and moderately annoying for me. It's not like a world of difference, Im sure I'd get used to it over time and just forget about the trade offs.
Comparing the amount of text, size of text, etc. to each of the Pro vs. Pro Max sized phones viewing the same app or web pages, I couldn't really see a significant difference that was worth the trade offs for me. I'll miss the battery life the most, but as I don't watch a lot of videos or media on my phone, I didn't think anything else was really that useful for me.
It just comes down to personal preference here. You won't really know till you try it out for a day (or more... you probably do get more "used" to it, but I didn't need / want to get used to it. I just wanted my pocketable light phone back ASAP!).