According to my mom who's a born and raised Scot, salted is for those that don't use butter fast enough. She says it's salted so it lasts longer in your fridge. I only buy unsalted, I only cook using real butter. You won't find any simulated butter spread in our house.
I've told this before but it fits here. Years ago I had an old camp trailer that we used for a storage shed for 10 years (verified by the date on the license plate). I cleaned it out to sell and found a pound of unopened margarine in the ice box from the last time I'd used it. It had no mold, no drying out. It looked just like the day I put it there 10 years before. Anything that can last 10 years in a hot/freezing camp trailer without deteriorating isn't food. I haven't knowingly eaten margarine since.
Salted for me and mine.
