How many years have I been making this stuff, right? And I've always found it too sweet, no matter what I did. Until tonight.
I had made a Devil's Food Cake for DS's birthday, and he wanted vanilla frosting. Since I used buttermilk for the cake, I decided to experiment and use it in place of milk or half and half to thin the frosting. ZZZOmigod, it is amazing! Took away that too-sweetness that I always taste, even though I salt it. And gave it a super-smooth, fluffy texture for spreading. I wish I could work with it tonight while it's fresh, but alas I have to keep it until tomorrow. We'll see how it does after being in the fridge overnight.
ah yes, I know that secret :D
Other things you can do is 1-2TB of softened cream cheese (any more than that and you'll get cream cheese taste) --- mix the cream cheese and butter first together both at room temp (or the cream cheese even nuked a little til really soft).
Another is to use half butter half marscapone cheese --- the slight tangy of the marscapone will take away the sweet of the sugar.