The respawned enemies are NOT a bug
ED is indeed more difficult than DKS, even on nightmare mode.
I very like FoV because of the quests, NPC's and many funny things with a awesome atmosphere too !
But I can understand you talking about "the equipment" :
if I really put all my efforts in Ego draconis part of DKS my hero become very powerful (overpowered) and then FoV gear you find isn't THAT great anymore, except a few special pieces ...
This knowing I'm planning now to NOT try to get out all of the first part(ED) so it is more fun finding better equipment in FoV !