Iltifat Husain, MD
Would have to agree with David here — spot on. It really isn’t about the data storage and also the screen resolution — both are quite capable of both.
If anything, the 6+ has the biggest advantage for medical professionals, which is the iOS platform. Anytime someone is making software for medical professionals, they focus on iOS first since a majority of physicians are on that platform. So if you’re viewing radiology images, the DICOM you are using, or the streaming software you are using is most likely going to be tuned for iOS first.
When it comes to storage size — usually for radiology images they are coming from a central server, so size on your phone doesn’t matter, unless for some reason you want to store the images directly to your phone (odd?).
But like David said, if you want to really tinker with a device, add super custom features, go with Android. If you want a device that is tuned for medical professionals first by the developers who create software for doctors, then go with iOS, the 6+.