Most stable kernel after 3.8.x?

What’s the most stable kernel we’ve got for the BBB that also fixes the USB problems that exist in 3.8.x?

Here, the esteemed R. C. Nelson says that 3.14 has been more reliable for him:

I’ve been running into random reboots, every 12 hours or so on average with the 3.17.0-bone4 kernel on a rev C BBB.

I have a pile of 10 BBB’s at my disposal and some time to test different kernels. Does anyone have a particular release that has served them well?