To be honest, no I haven't, but that is also a card i could have in sideboard. I have yet to put the deck together, I've been finishing a Legacy deck, which is now about 5 cards from being finished for real. This is the next project!
But that is an idea for sure for sideboard i think. The only issue is having to splash a third color, could ultimately slow the deck down quite quick
Also, it is just better to play Viscera Seer or a free sac outlet if you want to use the combo..
i don't understand why you would need unlife in the sideboard?
I thought about it, and am not going to run it, at all... it really is not worth the change in mana to use.. and I feel that the deck is quite viable without the need of it.