I have tons of digital FPV. DJI O3, DJI Vista, Walksnail, etc. although I tried it, I was not a fan of FPV on planes. There is no such thing as smooth FPV on a plane, and the visibility on most planes is abysmal. No, I do not think any FPV on a plane is worth it.
Quads? Oh yeah, worth it and then some.