So far i havent seen any real bricking reported on this update, if you can format the harddrive and bring the PS3 back it would a stretch to call it a brick.
I think any situation in which all of your data is lost is a serious one. If it happened to me, I certainly wouldn't be very pleased, I'll say that much. But it doesn't even have to happen to me at all for me to say that this is probably the worst-executed of all their firmware updates to date (in terms of dangerous side-effects), and as such, I don't see how it can earn the "extremely good" QC honor.
Now I'm not saying in the aggregate it's a big deal, because truthfully the effects overall aren't all that dramatic. But saying it's not that bad and actually praising it IMO are two entirely different ideas.