Well… both my LH18A1P drives love most media burnt well with low jitter @ 4x. If the average jitter level is below 8.5%, the disc usually scans @ 16x without major increase in errors. Of course I’ve had strange discs with low jitter and errors, show massive increase in PIE @ high speed scanning, but that’s very rare.
That’s why I think jitter is important. Usually, with a disc like the one you posted, the PIE can (not always) go up when you scan @ high speed. Simply because jitter is fairly high, and as your drive reaches it’s highest speeds, it becomes harder to read poorly formed pits and lands than it would @ 4x. Thus the PIE will increase, but not usually the PIF, unless it’s a poor burn.
So that’s a good thing that your disc did not increase greatly in PIF.
I’ll just say what you already know, that disc is ok for normal use but I wouldn’t rely on it to be perfectly readable in all players. I wouldn’t chuck out a disc like that just because it scanned bad @ 16x. If it does ever have some playback troubles though, you will at least have some sort of answer as to why
This is a scan of one of my good discs. Most of my well burnt media will scan fine @ 16x like this, even if it’s TDK, as long as the jitter is very low to begin with.