DBoS has just as much burst damage, it does more follow-up damage (as in the DoT that's placed on your opponent from DBoS out-damages the extra damage you'll get from Incap) except unlike Incap you'll hit and CC multiple targets, it's undodgeable, and it passively increases the strength of your other abilities by having it slotted.
The Minor Mangle you get on Incap is honestly pretty useless. I tested Incap to see if the damage gets applied after the health reduction (was trying to justify using Incap still) and it does not; also the duration of Minor Mangle is only 5 seconds which doesn't even make it impactful.
The only reason why Incap was worth using in PvP was purely for its Defile, and in PvE Soul Harvest is debateably better.
ZOS if you don't return Major Defile to Incap you've effectively deleted the ability from the game, and have reduce Nightblades to being another stam class that uses Dawnbreaker.
On a side note, I plan on using Soul Harvest next update in BGs and in PvE so Stamblades will be able to maintain some identity in those contexts. In CP PvP however you're just handicapping yourself by not using DBoS if these changes go live.