From their site:
"San Diego IPA, as it has come to be known by many, is pale in color, super-hoppy, high-gravity, yet a highly quaffable ale. Our Imperial IPA is created in this new tradition with intense hop flavors and aromas from a unique blend of Summit and Nugget hops."
It's those summit. I think I could pick out that flavor in any beer that used even one pellet of it.