Sorry for the late reply mithchmarkl, nrg,

Have tried discrete codes on NVFJ630, NVHS830, NVHD685, NVHS960 (if I can remember rightly)
mainly used for discrete on/off although I did try the discrete AV codes with positive results (NVHD685 definitely worked although is now an old model)

In general the results were fairly consistent.

Please note that these are European models (can't speak for models in the States as I don't live there)

As for the OFA/RS remote question - no idea as I've never used them, Sorry.