I've been using FSRealistic for a week+ now and it's been great to have some added camera movements available and it certainly adds to the situations enabled.
Is 15-25% GPU usage the average? It's using ~1% CPU which is great but I noticed the GPU usage spiking pretty heavily the last few times I've loaded in.
Now that I'm watching it for an even longer period of time, just loading up and prior to take off it's taking ~30% GPU almost steady with the plane not even started up and sitting.