Ah, I should have read your original post more carefully. Sorry about that.

So, in that case, let me say a little more about the Sprintech mirror. It's pretty stable, but it doesn't give you a clear picture of things in anything less than ideal lighting/contrast conditions. For instance, dark-colored cars with their headlights off tend to disappear in the road on overcast days until they're fairly close. Cars with their lights on, on the other hand, are generally easy to detect in most conditions. I don't think I would trust my life to this mirror in terms of whether or not it is safe to change lanes, but it does give me reliable hints as to what's coming up behind me.

The other problem I have with this mirror is that when I'm riding in the drops, my view of the mirror is blocked by my arm unless I consciously stick my elbow way out. It's not insurmountable, but it's inconvenient.

I think if I were in your position, I would want a mirror with a bigger surface area.