Works fine, though the side buttons don't work. I'm not sure if it's hardware or software, but a lot of people seem to have the same issue with mixed results on fixing it. I've since upgraded to an MSI mouse and just want this out of the way. Selling as is where is:

Ditch the Wires, Keep the Performance The Sensei Wireless is SteelSeries’ innovative ambidextrous premium laser mouse designed for the gamer who values lag-free trusted Sensei performance and outstanding beauty. Delivering uncompromising freedom from wires, unparalleled performance, maximum customization and a stand-out-from-the-crowd look, this mouse proves that sometimes beauty is more than skin deep.

Tournament Grade, Full Sensei Performance SteelSeries delivers tournament-grade performance in a wireless mouse. Sensei Wireless erases all the preconceived notions that wireless mice have faced over the years and meets or exceeds every performance spec of its wired predecessor. Equipped with one of the highest polling rate on the market (1000 Hz), the Sensei Wireless delivers a 1ms response time that eliminates wireless lag. The Pixart ADNS 9800 laser sensor allows you to ramp up the CPI to 8200. To top it off, its highly-responsive SteelSeries switches have a lifespan of 30 million clicks. Maintain your winning edge by personalizing and fine tuning settings including the lift distance, button functionality, and CPI.