Samuel Smith's Imperial Stout

Apparently my son and son-in-law are beer hounds when they visit my place. I've got to increase my production so I stop running out. Anyways, I broke down and actually paid $$ for beer. After 20 minutes and several reverse decisions I walked out of the liquor store with Samuel Smith's Imperial Stout. Being a strong stout guy this stuff is great. Very smooth, a heavy mouthfeel, great head and retention, 7% ABV, and a really good flavor. Just what I was looking for.

Has anyone had this before and could compare this to a homebrew I.S.? I've been thinking of an I.S. to be my first partial mash batch so a proven I.S. partial mash recipe would be greatly appreciated.

Tks,

Paul