Review (4/5): Nice balance between soft and firm; some fitment issues
This is a good middle ground between the standard Oral-B brand brushes and the Ultra Soft Oral-B brand brushes. I find the standard brush to be a bit too firm and, while I like the softness of the Ultra Soft, sometimes I'd like just a bit more firmness to the bristles. This is a good compromise. It's softer than the standard but firmer than the Ultra Soft.
On the downside, it does not fit as well as the authentic Oral-B brushes. It's a little bit loose, which causes it to be noisier in operation than an authentic brush. It still works fine and stays on firm enough so there's no danger of it coming off in use, but there's enough play in the fit that it's more buzzy than an authentic.
Even with the fit issue, this is a decent alternative to the Oral-B brand brushes and a solid 4-star brush.