My 15 Pro Max is going back today.
Coming from a 13 Pro I found it very difficult to hold and use with one hand (and I've got big hands), it's not very portable and I couldn't get a solid grip on the titanium. It felt very slippy. With a case on it would have been even more difficult to use. The screen felt fluid and I guess the camera is better but it's just not a 'mobile' phone in my opinion and it was quite an underwhelming device (this could be due to my age and tech fatigue though).
I don't know if I will stick with my 13 Pro now, or look at the 15 Pro.