[dnanian]

Yes, it's important to note (again) that if it's taking a little extra time in some situations in this version, and if the backup takes up more space at a low level, the copy is still reflective of the source and is valid... continued improvements will be made as we determine the cause.

Usually, this kind of thing is investigated in testing, and although we've been in test for a long time, the 'seems a bit slower/added copying' issue came up relatively late, in the "gold bits" timeframe, and then Snow Leopard shipped about 4 weeks earlier than we expected. It was unexpected, and we didn't consider it wise to make risky changes late-cycle, since the copy itself was OK, and there just wasn't enough time to get into the low-level details.

We could have delayed weeks to try to figure it out... but considering how people reacted last time we needed to delay, and since it was a performance issue and not a copy problem, we decided to go with what we had.

Now that we have a bit more time to investigate more completely, we're working on it, and if the fix is riskier, we have the luxury -- necessity, really -- of being able to test it without the same deadline breathing down our neck.