I'm thinking about getting some kind of device for my bike. Primarily, I'd like to use it for GPS/navigation. I lead occasional group rides or sometimes like to try new routes. Currently, I have the routes loaded onto my phone which I store in a ziplock in my jersey pocket. Whenever I'm uncertain about where to go, I'll stop and do a check, but I hate making frequent stops when there are multiple short turns.

So I'm thinking about simply getting a bike mount, like the quad lock. It's pricey but seems to do the trick.

Here's my question: if I mount my phone, are the vibrations going to mess it up over time? I have an iphone 6s plus which has great battery life (great for long rides) but some people claim the rattling is bad for the camera/motherboard, etc. Anyone have any experience with this?

A second noob question: Do the GPS computers have any advantage over simply using a phone w/ a bike fitness app? I thought it might be price, but those computers aren't particularly cheap and since I have to carry my phone anyway, I hate to have to be laden down with multiple devices.

Another option I've been mulling over is a fitness watch (maybe the Apple Watch 2 when it comes out). Most don't offer directions/navigation alerts...

Thanks for your time!