I have two of them. One with the felt and another that I applied Velcro strips to (it comes with both). The Velcro is pure magic for cleaning the wheels on cars. I'm not quite as impressed with the felt strips, but for lighter cleaning they do work well and are long enough to accommodate an entire loco at once, something that the shorter length of the brass wire brush type doesn't accomplish. Still, for heavier duty cleaning I do have two of the brass brushes mounted together because they will take off things that the felt and Velcro just won't.
I'd highly recommend getting these, if nothing else for cleaning the wheels on your rolling stock. Like I said, they do work wonderfully especially for that.