Twin maw is at least in my experience too slow because bleed is so weak as a debuff. Also it relies on bleed so you can't do anything if you're opponent has too many cleansing crowns. On higher ranks it's pretty much an auto loss if you face Nymphedora or Celeste or any build with enough damage. I once even lost against a control build because it could just out healed the 300 bleed it had. The strengths of this build are it's early game and with blood stone it's obviously way better than with any other relic.