My blade is swifter

I prefer diffusal/treds is it buffs your illusions with manta style, allows you to have a slow, great situationally (e.g darkseer, omniknight, warlock) and most importantly, with increased attack speed you can attack far more during your omnislash and drain manta, i did overlook satanic so i'll put that there, and I did put phase as situation in the case that your not laning with someone with stuns/slows (veno/cm best examples)

Why Diffusal Blade ? Better get a Satanic or a Butterfly.

Also Phase Boots are better for you, chasing enemies, getting away, easier Blade Fury, etc.