What annoys me to no end in NV drivers is that you can't pair different cards in SLI even if they have the same GPUs. I want at least TITAN SLI performance and never have I used it's FP64 capability. Why can't I buy an FP64 castrated GK110 and enjoy the same performance as two TITANS. Only greed from NV explains that. QUAD SLI scaling is also not very good so TITAN Z with a TITAN BLACK could be a good buy for an NV enthusiast with a thick wallet or TITAN-Z + 2x780TI if someone wants QUAD SLI and save some money. Of course none of that is possible in NV land, they are like Apple and they know better then you what's best for you.
There is one thing I would like to warn you about potential benchmarks, unless they are done with the card already warned up they are useless the card can lose 15-30% of performance in 10 minutes. Fortunately it can be mitigated on a regular Titan by increasing temperature target and fan speed but I don't know if you can keep full boost without making the card very noisy.
ps. this is not GTX590 it's not a bad card I hope its PCB is robust enough to not blow itself. I like the card a lot but I hate the price even more.