Don't believe the batch # hype, I think this has been proven to be an urban myth nowadays. One chip in the same batch may do really well while another is piss-poor.
Now just going by my own experience, I can only recommend Ivy setup as it runs cooler allowing better clocks. However, a Haswell running at 4.4giggles is the same as Ivy running 4.6giggles (my personal finding on my chips) so that would suggest a Haswell.
Secondly, you can always get the tuning-plan.. wait until Intel brings a new revision on the chips and then change it over (you know what I mean..). The newer Ivys are better than the first lot so my expectation is the same for Haswell, again suggesting a Haswell buy is a better option.
"We must let go of the life we have planned, so as to accept the one that is waiting for us."