You don't actually need that much skill speed like others are saying. Blood weapon can get 5 full hits with slower GCDs, although it takes some getting used to on pressing the button slightly later in your GCD than with other typical 10 second buffs. I've been able to get all 5 hits up to 2.42 (others can do it even slower, but I'm in the south!), though I prefer the consistency of 2.40. That said, you'll get more consistent numbers if you go with melding det and crit, but you'll be able to achieve higher numbers with crit and direct hit, though if the difference is worth it is up to you.