Yup. The Flesh Tearers really are among the most bloodthirsty and out-of-control Chapters, and are a strong contender for the No.1 slot. The nobilty of the Angels is all but gone and they're pretty much to a man on the verge of becoming frothing berserkers (who think they're Sanguinius). Their gene-seed is horribly flawed - how they get around the purity tests is worthy of consideration -I wouldn't be surprised if they were doing what the Black Dragons are implied to do, taking the gene-seed of other Chapters.
Gabriel Seth, Chapter-Master, is no exception but he's actually a pretty good leader, always trying to keep his Chapter from more public battlefields and eve fighting alongisde other Imperial forces. They really, really cannot restrain themselves, hence their vastly reduced numbers - a dying Chapter, really - they're not the sort to hold off deployment until their number replenish and more of them go irrevocably insane every year.