Just a quick look at the MX Ergo. There were a few things no one seemed to mention in their reviews I watched before purchase so I mentioned them here. Two issues I had to ask on Amazon to find out the answers and the 3rd issue I never even thought of until it arrived. Those issues or points of interest were "Can you pop the ball out like the old version and does it still run on rollers". The answer is yes, it still runs on rollers. Second issue is it has a internal rechargable battery which has annoyed me slightly. I liked being able to just pop in a AA battery. The third issue which no one appears to have mentioned that really has annoyed me, is no storage compartment for the dongle. I take mine to work every day and don't want to leave the dongle in the work laptop. With the old version I can just pop it in its compartment. The new version I have to find somewhere to store it. Super annoying. The precision button appears like a gimick to me and is just a quick way to really slow down the mouse pointer instead of going into Control Panel. I feel it's still overpriced despite being slightly discounted on Amazon and having used for half a day today at work in the new tilt mode, it started to become uncomfortable. I'm at a point now where I'm considering returning it. ... https://www.youtube.com/watch?v=2pmabnNOR1Y