I found no matter where I buy batteries it's a crap shoot. I buy a fair amount each yr and now I buy all my batteries from napa. I have had decent luck with their legends. Much better than what I get at oreilly's or batteries plus. I do like duralast golds from autozone and have had REALLY good luck with them over the yrs, but I just hate autozone and won't go there just for batteries.
napa takes care of my needs/warranties. When I buy a dozen, or maybe 20+ batteries some yrs, it's nice to buy them all at the same place for warranty. I also find them to be 10-20% cheaper than other places.
I have a honda odyssey that ate up two OEM batteries in 6 yrs that I just replaced about 10 months ago with a napa legend. curious to see how it lasts considering I think the van is hard on batteries.
If costco were closer to me, I might give them a shot with interstate. I bought an S2000 with one it. has been good for this season. I'll be interested in how long it lasts for me and I'll have to see if there is a date code on it