Are you a photographer who wants to shoot occasional video or are you a videographer that occasionally shoots photos? Are you a macro photographer or a wide angle type guy? I just got my wife a killer GoPro rig for our anniversary, the new AOI GoPro case ($$$) which comes with a 5" LCD screen and full controls, a Sola 15K lumens video light that is mounted on top, and a GoPro 12 (27MP). She is a videographer that never shoots photos except by accident. A wide angle lens is mounted. Other than having two lights, that is state of the art. I on the other had, have an Olympus TG-6 with two Inon D-240z strobes. I never shoot anything but macro, and the occasional video of a macro subject where movement is interesting, although you can certainly take wide angle shots and mount a wide angle lens on the case. If you are a video type guy, the GoPro 12 is definitely the way to go, although you might not want to spring for the AOI case ($1500). I would not recommend a mask mount or a stick. The GoPro 12 has very good stabilization, but you need to see what you are filming, make sure that your settings aren't messed up, and you need to be able to stop/go without too much screwing around underwater. Putting the GoPro on a tray makes it easy to stabilize, and see what you are doing. A stick gave me jerky video, that induces vertigo, LOL!
If you are more of a macro or photograph guy, get a TG-7. A phenomenal and flexible camera that the Nauticam rep called the industry's "dirty little secret" because it takes such great shots, especially macro. During a photo workshop in Lembeh Straits, my shots were generally as good (but of course, not always . . . there were some very good photographers in the workshop with very expensive gigantic rigs) as the giant rigs. You can always screw on a wide angle lens for it. The photos blow away what you can get from a GoPro, and without a macro lens, the GoPro is useless for true macro.