hmmm.. with d3up, my manticore with 1 socket marquise ruby the other radiant star emerald, the increase is 8k damage. Not much for manticore users but at my current state, even putting up 5k dps costs 300M so the marquise is welcomed in one of my sockets.

Yeah, i think it would be but the marquise ruby must have a viable range or it will be deemed useless and another failure which I think Blizzard will try to avoid. It MUST have substantial damage as they claim that it will be able to go head to head with Emerald.