Bittercut is a very, very good weapon:
1. Starts with +20% from sabre bonus, get's +20% from Spirit of Decay before any other enchantments are applied.
2. The Bonus from Spirit of Decay applies to both the slash and corrode portions of the weapon
3. Any lashes will synergise with their respective elemental talent e.g. if you put a corrode lash on bittercut and have spirit of decay, it'll become a 30% lash rather than a 25% lash.
4. Dual damage types are really, really good.
5. Vulnerable attack with apply to both the physical and corrode aspects of the damage. However, given that Rogues can struggle with getting speed boosts, other than in situations where you're dual wielding, you might consider something else instead because rogues dont have too much trouble with DR through doing high damage. This'll depend on the rest of your equip set-up though.
Another option to consider for rogue is the greatsword Tidefall. Rogues can dump Int with very little repercussions, meaning the wounding effect will work faster. Draining is fantastic. Tidefall has two damage types as well and comes Superb as standard.
Edited by Livegood118, 19 March 2017 - 03:41 PM.