Bike eye doesn't work great if you have certain bags/panniers or rack top ones. You need to try it out to really tell.
Other than that, it's the best mirror I've used. Seems to be less effected by vibration too. I've used several helmet mirrors and two bar end styles (Italian road mirror and another one that's more adjustable). I like this the best by far.
They have a video on their website so you can see how it works.
J.