I love my Mountain Myrricle, and won't ride without them.

With a good mirror it is so much easier to anticipate what is going to happen.

I can watch traffic behind me to see if they are starting to give me room, or not. Then I can take action accordingly. Be it the nervous beginner wobble, take the lane completely, or move over.

Some folks say they make the bike too wide - it's just a matter of how you set them up. I aim the first stalk (the one closest to the bars) straight forward, and the second one straight up. Then adjust the mirror, and lastly the stalks for a good view. This way, the added width is just barely wider than 1/2 of the actual mirror width, and still gives a good view.

Sure makes riding less stressful.