Yes, a bigger display is way better. Fortunately, with a good glasses prescription, the iPhone charting works for me too. We use it all the time for augmenting our failing memories about places. Just pulled it out to locate a Kiwi friend's home on the South Island when she came to the US.

We upgraded to an iPad Air, got a Lifeproof Nüüd waterproof case and a Ram Mount X-Grip holder. A double U-clamp with swivel ball stays on the pedestal guard and the rest can be removed in a jiffy when not using the iPad. This is a supplement to our still-serviceable chart plotter under the dodger, but is way more versatile for zooming and positioning the view. We bought a swivel option so I can achieve a head-up display even though that is not native feature on the Navionics app. The mount is quite sturdy, but I wouldn't want to get a loaded jib sheet wrapped around it. I'll post a picture some time.