Agree somewhat with weebitbrieezy... most of the videos showing foiling in surf are pretty marginal. Most of the time they are way in front of wave in the flats, far down the line ahead of the curl, or maybe zip in for a quick turn, but not really riding the wave. However, there's a few out there where foilers are on the wave face and doing some decent carves.
The trend to mid-aspect freeride/surf focused wings has only just started in the last year or two. Now that people are realizing its not all about how fast you can go, but that riding waves requires slowing down and good turning ability, I think we'll see more interesting wave riding videos coming up.
For me, I am a surfer first, I'll be on a surfboard if it's good. Foil is for playing around in between surf sessions. However, what has turned out to be super fun is foiling when there's decent size rolling wind swells. You can really feel the acceleration when you catch the wave and drop in. On a good downwind reach, you can ride the same set for a long time ... and it is the closest thing I've felt to the weightless powder snowboarding, silently, smoothly carving, with the kite just sitting there drifting.
So...it isn't the big slashes and spray, but it's a pretty cool feeling. I figure that's what dolphins are after when surfing ... they don't ride in the curl, but in the face on the steepening wave. The foil is similarly riding the energy in the water.
Anyways, final point ... I think this is one of those things that looks a little goofy but feels awesome.