Brendon Smalls does have a rather monotone voice, doesn't he? I've learned to tune vocals like that out by growing up listening to bands like Cannibal Corpse. It helps that I have always been more "band" motivated and tend to focus more on guitar, drums and bass over vocals. I enjoy growling vocals, but they have to be well done growling and follow a vocal melody, not just monotone grunting seeing how low they can go.