I've been working with GaN parts for RF after being out of the hardware game for a few years. GaN was around but nowhere near as prolific as it is now. I thought SiC would have made more inroads than it has. GaN parts just seem incredible in every way (to someone like me at least) - amazing performance, efficiency, power handling in such a small package, more impressive impedance matching on wideband parts - it's just a shame the basic problem of harmonics still hasn't been whisked away by magic :)