The failure mode of the Shimanos (105) wearing out, was that they no longer shifted... at all. I probably got about 15K on the two shifters combined. I may have just replaced it again with the same, except that it was 9 speed and it was becomes increasingly difficult to obtain parts. I'm not sure exactly how many miles I have on the SRAM, but probably in the area of 10K. However, the failure mode is that the shift lever does not always return on its own and I have to return it manually. It still shifts, and that's important.