Editing and uploading from a phone is nice, but it stays on the boat when you drop in.
It's also huge to have a screen as big as the phone's, and being able to slip the whole rig into my thigh pocket meant I took it on every dive, not just camera specific ones. I can't imagine a better setup for me.
Edit: You mentioned video. The Paralenz is a much better diving camera than a GoPro. It has a tubular form factor, making it easy to attach to a mask strap. It also is natively pressure resistant and can add depth numbers to your video, GoPros require a case. Here's a dive filmed with my Paralenz: https://m.youtube.com/watch?v=C1MEynCKlhk
The paralenz can't shoot high frame rate, so slo-mo looks choppy and requires serious post processing. It's stabilization is a joke compared to the GoPro, it doesn't shoot flat color so color grading is painful, it has no screen for checking your framing, and it costs roughly twice as much.
Edit: the quality of the glass in the paralenz is also pretty painful, the vignetting in that video and dynamic range are pretty unfortunate.