While I don’t have this brand’s copper bowl, I do have a Mauviel version which works well for beating eggs. No need for cream of tartar, and the bowl looks gorgeous when cleaned. With that said, be sure to clean it as soon as you’re done, and be prepared for the bowl to look oxidized over time once it’s used. It’s easy to clean the oxidation with a lemon sliced in half and rubbed ins salt (for tougher stains, I found toothpaste works very well).
I had a totally different thing in mind when I saw “beating bowl.”