I don't have the .28, but a few smaller ones. They seem fairly good, to real good in the case of the blue head one. I would think twice about a used one, or the older models. Most are a copy of the last model OS, so the design is fine, and the machining quality has improved a lot over the last 3 - 5 years. All motors have some kind of flaw, even the famous overpriced OS. Same company as Magnum, Sanye SC.....