What is a Good 4770k Batch #?

I recently sold my 3770k rig so Im looking to get something with the 4770k.

I've called a few places around my house and the three batch numbers Ive found so far are:

L307B187
3306B568 (Costa Rica Chip)
L315B386
3312B715

I've read the Costa Rica one is amazing but I still want some of your opinions.

Thanks