Review (3/5): Meh...
The idea is cute, but I'm not sure it's worth all the work. I felt like I spent more time in my wash process using this holder. And of course, it only holds so many brushes, so you are still left drying the remaining ones your usual way. I won't say I'll never use it again, but I wouldn't jump to pull it out (one pro is that it's collapsible so putting this away is a breeze).
I also felt it needed more smaller holes for smaller brushes. They should also manufacture this as a set, with one solely for large brushes and a second that is designed for smaller brushes. This way, more variety is offered, essentially increasing efficiency of the product.