To add. Of you read thru the site. I think you'll find that no one has ever said a Sparx sharpening is better than a really really good hand sharpening. It is however far more consistent and convenient. I was a Blackstone customer for years and currently own a Sparx. I have never once had a bad sharpening on my Sparx, never. I have however received uneven edges, incorrect hollows, burnt edges and ruined profiles from some very highly regarded hand sharpeners.
TBH, I think the market has spoken.