As a one-handed barb, Death Cleaver is now better than Grandfather if your only source of deadly strike is highlords and/or goreriders (goreriders would be a waste IMO if you use death cleaver & highlords - go with war travs). Now that the critical strike bug is gone, the 66% deadly strike brings its actual damage output in line (and even better in some situations) with Grandfather. Not only that, but its significantly faster as well, but it can't be used two-handed. For a barb merc, I'd definately go with doombringer (fast, good life bonus) or some ethereal rare cruel or ethereal runeword if you can get a hold of one - try a crescent moon ethereal legend sword possibly.
Grandfather as a two-handed weapon is an ok choice, but there are much better ones out there - even in 1.09. The +max damage made Grandfather useful because you could get really high damage using it one-handed.