Yes the trooper solo has a lot of trills in it, as well as a lot of other metal solos. Just think Randy Rhoads, Murray, Angus Young, Hendrix... It is helpful to learn any technique possible in the guitar, incluiding trills. Is it going to help you? Well yes, it will help develop strenght and dexterity in your fingers and it will help you run on scales with hammer on's and pulloff's with greater speed on other solos.