My opinion...
The black one is not a good idea.
With the way the beater rotates around the bowl, it's hard to scrape the bowl while mixer is running.
With the metal bowl, when making something like divinity where you add boiling syrup to beaten egg whites, it takes FOREVER for the bowl to cool enough to start to thicken the mix. And I mean FOREVER. I've wrapped ice in towels and held them around the bowl in an effort to cool the darm bowl.
Just my thoughts.
Scraping the bowl while it is running is a no no with this mixer.