I have a Roomba model 780. I have not noticed any significant difference in these parts compared to those that originally came with my Roomba. There were no problems with replacing filters and brushes. The size/feel/quality of the brush seems identical to the original and I didn't notice that the bristle brush and whisk brush were too close together as I've seen in some other reviews. Ever since I replaced the worn out brushes with these, Roomba seems to pick up pet hair and dirt much better again. I have 3 cats so the Roomba makes it a lot easier to deal with the tumbleweed that accumulates between vacuuming and it does its job well. The only downside to this set is that it doesn't come with the small screws for the side rotating brushes if you lose them and oddly only 9 filters come with it when you normally replace them in pairs. Otherwise a good replacement for the price.