I'm shopping too.

I have one friend that swears by his Quadlock. He crashed his mountain bike really bad a few months ago, wrecked the front wheel, and got banged up himself as well. He said when he walked over to get his bike after the crash the Quadlock was still holding the phone securely.

And have another friend that swears the Topeak mount is the best out there. (But he didn't crash his bike yet so don't know the results of what that would be)

I'm leaning towards the Quadlock but holding off because of the price.