Westbrook has a much more pronounced and cleaner lactic taste. I emailed them about their salt/coriander quantities and how they sour (lactobacillus, acid malt, sour mash, or lactic acid) bit they didn't give any info. Just recommended reading "brewing with wheat".
They sent me the same thing. So I bought it. Didn't really have any info that I couldn't find on here or with a google search though. I guess its nice to have it all compiled in one place though.