I have used a Mini 4, and iPhone, and the Epson BT-300 glasses. No device, except the Epson BT-300 glasses, used with a big brim baseball cap, worked well in bright sunny days. All forms of glare shields or anti-glare screens failed to enable the kind of crisp, saturated, non-glare presentation that is possible with the BT-300. Having said that, the BT-300 is the most expensive and takes the most setup or take down time.
When doing still photography, I find the requirement to fly to capture position and back can most easily be done with a simple iPhone. Most of my flying is strictly VLOS as I use the drone as an extended tripod. The iPhone satisfies all requirements necessary to frame the shot when the camera is in position.
When doing video photography, most video is taken in short clips. Again, an iPhone is a simple device, combined with VLOS to position the camera for the start of a "take". Then, the actual short video capture efforts can be run by the drone's Intelligent Flight Modes. No need for BT-300's or a larger screen such as an iPad.