I recently farmed all the armour exotics for all 3 of my characters, didnt take allot of runs to get them all.
So for now i only have to do the 3 new ones when they come out.
So my expirience doing lost sectors isnt that bad.
The only thing i didnt do yet is farming for better stats, or a better distribution of so i have no expirience in doing that.
It's heavily weighted to give you exotics you don't have so getting the initial drop on something isn't a bad grind really, but given how important stats are in the end game farming for decent Stat rolls is abysmal.