Yes, you are correct sir!
I checked and it was the same unit that I got back. I thought I read somewhere they replace with another unit to keep turnaround times low.
This actually makes me feel better knowing I got my unit back.
And yes, mine was a Blu ray drive replacement. One of the ones that got bricked with the 3.01 update.
Funnily enough, although Sony will still not admit there was a problem with one of the releases affecting a small # of drives, on the work order it has a Repair code of "Software Update".
I don't subscribe to the conspiracy theories out there, but I am disappointed Sony didn't come to the plate on this.