Just to close the loop, I purchased a Nissen from Fastlane yesterday. I talked to Phil first as I was concerned about it being like the original. He said it was almost exactly like the Behr and that no one had had problems.
I was concerned about getting it today, but it arrived by 10 AM, just as Phil said it would. Spent 2 hours putting it on and puttering around under the hood. It fit almost perfect and it seems to work fine. There is very little difference to the Behr. It fact I wondered if maybe Nissen was OEM at one time.
Thanks everyone for your input.