Ok, I haven't seen one run, yet, but Joe got his hands on one. Now, a little about Joe. He is not your average Joe when it comes to engines (and most everything else in this hobby). I think he has run about every engine out there and they all run GOOD when he gets 'em set up and tuned, so he has plenty of experience to make comparisons. He called me up after running this motor and was in AWE at how well it ran and how SMOOTH it was. Instant spool up and turning real close to a DA 100 on the same prop.