If, in particular, you are getting the same early spike in other burners, then it's clearly an issue with the batch of discs. Like I said, the early spike is not really any issue, but the errors near the edge are getting up there. I don't expect burning at 12x to resolve the errors at the edge, but there's a very good chance that they'll at least be less significant. And the difference in burn time is minor. If you get similar error levels at the edge with the rest of the discs even at 12x, I would definitely say you received a poor batch. Whether it's worth your time to consider an exchange or refund in that case would be up to you. I would not be happy with the max PIF level that high out of MCC004, but you probably won't have playback problems IMO. If you want, you can run a Transfer Rate test to see what, if any, slowdown you'll get at the edge of the disc. Any dip in speed is a sign of a less than ideal burn (assuming your computer itself doesn't create the slowdown, IE multitasking), but if it's only a minor slowdown it probably won't cause playback issues.