I wouldn't say formulaic so much as subtle repetition of instrumental theme, with different nuances. If I'm being simplistic, Clutch is basically the best bar band you've ever heard, with some really sultry tunes that stand out as bluesy rock masterpiece peppered throughout their discography. They've a very masculine sound with, as stated, excellent lyrical content. But they are heavily reminiscent of dirty bars where gearhead blue collar men drink simple beers. How you feel about that is obviously subjective. I dig it, a whole lot.