I'm as confused as anyone - but from what I've been reading in the forums, it seems that Rocna is sticking with the lower than originally spec'd 620, and Manson has been and is still using the bis80 (or whatever, I can't remember all the terms), which was the original Rocna spec. But you really should check for yourself - because it's hard to know what to believe.
The best resource I've found on the whole story is at YBW here:
Rocna Anchors acquired by Canada Metal Pacific - Page 170 - Yachting and Boating World Forums
The poster "neeves" is a journalist who has done a story on them for some mag. He seems to have the most accurate info on the steels and warranty issues. It's a crazy long thread with the typical crap slinging - so just start at the end and go back a few pages to find out what's up.
At this point, to me, it just comes down to price and confidence.