Not that it matters, but here is my recollection of Italian sausage growing up in Chicago in the 50's.
When dad said he was going to the butcher to pick up some sausage he'd ask what everyone wanted.
Sweet was the most mild, just a plain old Italian sausage, tasting mostly of fennel.
Mild was the next step up, I'd say the same as sweet but with more spice added.
Hot was hot, probably some red pepper flakes added to the mixture
And there was also extra hot, which almost no one ever wanted, probably cayenne added to the hot.
Now living in Tampa, I prefer SweetBay store brand Italian. Quite a bit of fennel, and as close to Chicago as I can remember.
I've had the Premio, and while it's good, just not as good as SweetBay.