A friend gave me a D&D Ultralight mirror to try with one of my road bikes and it has worked out great. I have limited peripheral vision in my left eye (lazy eye), which makes it hard for me to see to the left or in back without turning my whole head. Often I'd look several times before I felt secure that there wasn't anything behind me.
This mirror has been just the ticket for me; I'm more relaxed-it's so much easier to just check the mirror for activity. I bought a second mirror for my other drop bar bike so I don't have to switch them back and forth. Since I don't ride in the drops, it's not in the way.
I use a bar-end mirror on my Coda Sport, which has also worked out well for that set-up.
1990 Univega Alpina/(stock) gel saddle
2009 Specialized Dolce Elite/BG Lithia saddle
2009 Jamis Coda Sport/Selle Royale Respiro saddle
2010 Jamis Aurora/Jamis Touring Sport saddle