Great with minor flaw
I found your question because I Googled the Vizor Sun to email the link to a friend because I can't stop talking about this product. First, the sound clarity is really, really good. So far, everyone on the other end says they hear me very well, and I hear all calls without straining to hear them. Plus it's pretty awesome looking. Don't pay attention to the reviews on Apple Store, or the bad ones at least. I almost didn't buy it because of them, but Apple had this on their 1 Day Sale last week, so I went for it.
Now for the bad part: the power button is awkwardly placed and hard to manage. The Vizor Sun attaches to either a metal visor clip or a dashboard metal attachment and magnets. When you go to push the power button, you dislodge the unit from the clips. Very annoying. Highly recommend otherwise. I went through 2 high end ear pieces, and was turned off by the whole "hands free" experience, until this gadget. Now I comply with California law, yeah!
My only recommendation: the instructions claim to charge the unit for 6 hours. Play it safe, keep it plugged in to your cigarette lighter for 24 hours, then pair up with your phone. Then, your good to go on the photocell charging feature.
Store website it seems like an exceptional product, but don't take my word for it