Murray, are you experienced with stainless steel? I'm not a luthier, but I was a diemaker, and stainless steel is a very difficult material to work. It's not harder than your diamond files, but it's gummy and could clog them more quickly than standard fret material.
Is it my imagination, or are new frets softer than they used to be? It seemed to take forever for my guitars to need fretwork, but I've bought instruments recently that needed partial re-frets after three years or so. Don't suppose it could be my ham-fisted stranglehold on the instrument? Nah.
Anyway, if there's nothing wrong with the frets, I'd leave them alone, but when it's time to replace them, I'd say the harder , the better.
Good luck, and please let us know what happens if you make the switch.