The SMH10R is fantastic, however, there are serious tech issue that make updating the firmware an unnecessary nightmare.  I recently "bricked" one of my two units, which sent me into a panic.  Correct troubleshooting steps at the end.

My Windows 10 machines (two of them) can't see the SMH10R at all.  Windows 8.1 can see them, but fails at everything past "Device Recognition."  Since nothing can be done here since "no harm, no foul."

Where I ran into trouble was with my Mac laptop, I am a full admin on this laptop. The Mac could see the device without an issue and the firmware started the update, but at 7% it failed and "bricked" the device.  It would no longer turn on and attempts to reinstall the firmware failed as the device could not be seen.  Pressing the "soft reset" button with a paperclip allowed the device to be seen, but firmware stated version "0.0". Subsequent attempts kept failing anywhere between 6% and 12%. The final error was "cannot update the next block."

The problem is driver signing. As good as Sena is at the underlying technology, they are refusing to take ownership of the software. Which seems odd.  Driver signing is super cheap and a requirement for all newer OS's. 

The workaround was to find an older OS. The oldest I could find was a Windows 7 laptop. Once I turned off driver signing (you'll just need to Google this) and rebooted, the device updated on the first attempt.  

The lack of driver signing is an issue with all newer OS's and seems to be the main cause for connectivity issues.  While Windows 10 can also turn off driver signing (again Google it for the steps), I was not able to do it my PCs use bitlocker. Again, this would not have been an issue at all if Sena will just sign the drivers that they are using.  

Hope this helps.