I was using the RMAed stick of Ballistix PC4000 until I could get around to selling it and replacing the RAM, and some other RAM of theirs with a different manufacturer. I was even feeling bad about my harsh words in a thread in the staff forums here. I was trying to keep a lid on myself.
Not anymore. The RAM died dead as a doornail today running at a cool temperature, possibily through a newer advancement of some type in the replacement module. The voltage was 2.8v, which is recommended, and it was running somewhat shy of PC4000 speed in single-channel mode with extensively researched timings values. The part number still exists on store pages at their website, but it is not available for sale again yet. I no longer wonder why.
I believe they still haven't gotten it right, and they did so at my, and I suspect many other people's expense. The only regret I have is obvious.