Hello all, I'm new (today) to Massdrop - but I can not recommended the Corsair M40 mouse at all.
I have one - I purchased it through an EGG shaped electronics online retailer, and have had the M40 die twice on me in less than a year. Once less than thirty day after purchase so the EGG shaped retailer replaced and then 93 days later I had to go through Corsairs warranty program.
After 65 days of fighting with Corsair I think they just gave up and sent me a replacement M40 - not because they wanted to, simply to shut me up, so they would not have to listen to me rant at them sometime three calls a day.
DO NOT (in my opinion) MASSDROP a Corsair M40 mouse.
I'll never buy Corsair (anything) ever again.