I fly predominately FPV with googles. Several years now and specifically closing in on one year with the H.
1) LOS is actually really boring.
2) I flew LOS yesterday at pre-dawn trying to catch moonbeams (failed). It is tough looking at the H, then the display, then the H, then the display to frame the shot, then the H, then the display .. and so on. It is to me disorientating and I really can't the frame the shot as well. I don't feel connected to the bird. I didn't loose the moonbeams due to LOS: they just did not want to play with me.
3) At 50 yards with LOS I can't tell the actual distance to the subject I am filming - 1 foot, 5 feet, 10 feet? With FPV, at 10 yards to 100 yards to 300 yards I know I am a few feet away.
4) WIFI in the H is awesome with FPV. The prior 5.8 analog was always like watching a 60's TV show where you can see the main characters but not a lot of detail and a lot of blurry edges. The WIFI HD with the H is terrific with the detail. I have no lagging effect - including 1 foot (or less) over ocean waves. I do not fly fast and do not race.
5) Lateral movements (rolling right or left) while looking ahead are difficult. There are no side mirrors. You have to know your area you are flying in and have a spotter for doing FPV.
6) Low flying over waves is incredible with the HD FPV on the H. It really is.
7) Knowing the shot you are getting with the feeling of the sitting in the camera is great. I am still 'slowing' down the shots and trying to hold on to the 10 second rule for video, but flying with the shot and adjusting to the immediate condition in front of you is compelling.
8) Another issue is not being able to adjust the ST16 touch screen. Pretty much once the googles are on, your video and photo settings and other touch screen options are off limits.
9) You have to know the position of the other control switches for camera tilt, rabbit/turtle slide, landing gear, RTH, etc., without looking. No kidding.
10) It takes a bit to get orientated to direction the H is relative to yourself. Be sure you are facing the H during flight and pointing the ST16 at it; sit up straight, don't get hunched over; don't get sea-sick as this happens initially; be able to rip the googles off and face directly the H and know the orientation and fly it back; be aware of people around you (really don't even try it in populated areas - FPV or not).
11) Work with the big green arrow to gain confidence in flying the H back to you based on that and not the actual view - i.e., trust the information the H gives you without actually seeing it. This includes altitude, speed, distance, direction. And especially voltage.
12) Actually get a practice drone and fly FPV in the backyard without overdoing it (no 200 foot flights, neighbors yard, chasing the cat, etc.) to get the orientation and sea-sickness out of the way.
Googles :
Headplay, but I will be purchasing the Avegant Glyph when I can as they allow a LOS and the FPV view. I am selling my old Fatshark googles as they do not compare at all.