Own the ultra 3 in natural with the natural Milanese band and own the ultra 2 in black with the black Milanese band.
I also own about 11 bands. First off, I would think about which band you want. It’s obvious which ones I prefer by a landslide!!! The Milanese band looks great and is the most comfortable watch band I have owned, Apple Watch or other. If you like to switch bands often, the natural is the way to go. Almost every band looks great with it.The black will limit your choice of bands.
As to which one I prefer……I tend to grab the black more often. It just seems smaller and less in your face than the natural. I’ve had the black since launch day and the finish is perfect,I’m not easy on watches so even I am surprised by how well it has held up. I had the natural ultra 1 since launch and thus that was the one that got upgraded. So I have been wearing natural for a few years. I will say that in the summer I tend more towards the natural. Must be the clothes I wear, can’t really explain it.
As I look at them now and think if I had to give one up…not that I would, I enjoy having both watches…..it would probably be the natural. I don’t switch bands anymore and that is a factor as well.
So my rather long answer is the black. Good luck with your decision.