On the mechanical switches I found that my Deathadder would start double left clicking every 2 years almost to the day but I always went back because I've never been able to find anything close to it's comfort I'm currently using a v2 hyperspeed which is still mechanical and this has lasted a long time 4 years now although I don't hammer it like I used to since I'm mostly controller.
The newer optical switches should last a lot longer and the price is quite good so I'd likely just buy a v3 when anything happens to this.







