I have a 5/8 Dovo, 6/8 Dovo, and a 5/8 Ralf Aust. I like the 5/8 Aust the best. Although the weight / hand feel is comparable to the 5/8 Dovo, the shave / cut feels so much better.
I use a Heinrich L. Thater Finest 25mm Badger Silvertip. I got it based on recommendations here. Love it ! I went in the mid-size of the mm, but I think I may try a slightly smaller (22mm maybe) of the same quality. I haven't tried any other brushes so my thoughts may not be worth much, but hats off to all those on the forum that recommended it in their posts. I was not disappointed.