Who is the window manufacturer and how old are they? How extensive is the "softening"?

Do the screws holding the hardware to the wood sash feel solidly in place or are they loose?

Refacing partially rotted wood seems like a fool's errand to me. I agree that it's more like covering the problem than fixing it.

If the frames are good I think you would be better off looking at new sashes rather than trying to fix the old ones, unless the rot is relatively minor

when replacing wood or repairing you want to go back to solid wood. I prefer using wood vs epoxy for repairs in most cases. Dig into one and find out.

@oberon476 Builder grade windows - local co unknown - 25 yrs - the frames are good - will check the screws - its mainly softening in portions - not on entire sashes which is why I'm leaning toward epoxy and a good finish coat.

25 years on builder grade wood windows isn't bad at all. Hopefully they aren't rotted out too deep and epoxy can repair the damage so far.

Repairing a 25 year old builders grade window is like using bubble gum to hold a hair piece on a bald man’s head. It may do the trick for a few minutes.