I've got their MMO mouse, and it works very well and gives me more buttons than I need, so I'll probably switch to those.6 months?
Maybe you should try a different model from them, it might last longer. The shape of mine is very similar to it.
The MMO mouse has a much better cable, so I may try that. I have another one of the sensei already, so we'll see how long that one lasts. Last time I bought 2. I wasn't expecting to have to bring out the second one that quickly, though.
But strangely it is apparently the left mouse button wearing out. Those switches are supposed to last a very long time. I've got that Rat (Mad Catz) I can use too, so it may be awhile before I actually need to buy another mouse. I have a feeling the Rat will outlast every other mouse I've had for the last 5 years. It's simply a higher quality than the Sensei.