Do you not keep up to date with the rotation and talent guides?
Tier 100
Demon Blades.
The 7.1 changes to allow fury gain while on the GCD makes this talent superior to prepared for most players. Low-gear players may find more use out of Prepared, but this phase does not last long. With the legendary Havoc ring Demon Blades is a non-choice regardless of gear.
If you have the ring, it's a non-choice and it's awful. It's not supposed to be our best talent but there it is. Once you get the haste and the ring, your dps DOES go up a lot and it's fine then and only then. I can pad on some fights but doing actual good ST (which is most important for raids) requires the ring + belt/bracers. I understand I have pretty weak gear but I get destroyed on pretty much every fight in EN but 'Demon Hunters are fine'. Pft.