My larger planes 120 size and up are gas an now with the new gas engines I'm starting to convert the 50-90 size .  I'm currently running an EVO 10GX 10cc and it has as much power as it's glow equivalent and I can run 30+ minutes on 8 ounces.
I am still going to keep a few of the smaller glow 4-strokes in service but for the most part  what isn't already electric will  be gas....eventually.