Back when I was building kernels for embedded hardware (Sheevaplug) in the 2.6.33 timeframe, I found a USB audio regression between 2.6.33.7 and later versions. If there were a semi-turnkey way to set up a testbench that could automatically reboot hardware in every new kernel, run through some basic tests, and report any deviation, I probably would have been more likely to do so. At the time I was working solo trying to release a polished consumer product (sadly though the product was released the business didn't work out) and didn't have time to dig into and report bugs.