While the retention is good, I haven't had any issues with the phone falling (I road bike only, mountainbiking should be ok),

The clips that hold the side of the phone fell out of their guide track and were impossible to put back in.

After 3 months of use, the mount broke mid ride and the phone fell of the bike

I've been using this with my Sony Xperia - I found it pretty easy to install - took me about 10 minutes (if that!)I was worried that it might not be sturdy enough - my biggest fear being the phone falling off during a ride - but I've yet to experiene that with months of use

I recommend using a zip tie to attach to the rubber that secures the 4 corners of the phone to the bike handlebar in case the pedestal breaks and your phone falls from the bike (lesson learned)

I got quite a bit of use out of mine before it snapped off during a bike ride sending my phone to ground as I was cruising along

Very adjustable as for phone size as well as mounting bar size

It broke as I was installing it on my bike