Well, I’ve been using a 16” M3 at work for a while now and have the 14” at home.
The 16 is a brick, but no difference to my previous Intel 16” pro. The display is stunning though, with the 14” I often long for a bigger (or external) display; rarely so for the larger one.
Yeah, the 16" is much much heavier than I remember the 15 inch, although I haven't really used a 15 inch for a couple of years now, so my impression might be a little off.
The 14" M1 Max that I use today is basically perfect in terms of the blend of power and portability. And when I am back at home at a desk, I just plug it into two additional displays, and no issues with screen real-estate at all.
I think you can only justify the 16" if you for some reason cannot have an additional display at the desk. It is too heavy to lug around to use at conference, on a train, or at a coffee shop, and still not enough real-estate to truly work at a desk. Seems like the worst of both worlds.