That's pretty much my setup, but only the left side mirror, and closer to the bar ends. The Spy sits so close to the handlebars that it doesn't work well on the outside of the mirror for me (I mostly ride on the bar tops & brake hoods and found I had to contort my left arm to get a view of the Spy when it was outboard), but it works pretty well mounted inboard as in your picture. As a bonus, inboard mounting means the mirror is pretty well protected in cramped quarters, when leaning the bike against a wall, etc.

My old touring rig uses the classic Rhode Gear mirror that fastens to the brake hood. It's more effective, but no longer made, too thin for modern brake hoods, and I've come to prefer the stealthier Spy setup.

I know someone who uses a helmet-mounted mirror. It works OK for her *except* when biking away from a sunrise or sunset -- the mirror just reflects that intense light right into her eye. That's a problem I never had with bar-mounted mirrors.