In this day and age, "bad strings" have become a relatively rare occurence. The Dunlop RTTs (as they are called) are just overall balanced sounding roundwounds, covering all the right frequencies. If that is run of the mill to you or just right is a matter of taste.
I've been playing bass for 35 years now and I still don't have a favorite brand nor one I would absolutely not play. The RTTs are fine if you want your bass to sound like it sounds, eg not try to compensate something it lacks. I assume that RT pays active basses (he now has a signature Warwick), so you neither want or need extreme sounding strings, certainly not ones with pronounced mids as they would get in the way with the Metallica riffage. I expected them to sound more extreme than they do, they are well-tempered, not snarling monsters.