Here's what I personally think: These disks are very poor quality. They cause vibration in my Plextor drive and scan poorly in Nero CD-DVD Speed when scanned at Maximum or 8X. At a lower speed, 4X, the results are much better. Still PlexTools produces much better scans apparently due to the slower speed 2XCLV. I think Sony no longer cares about quality control like they once did: case in point: I bought a Combo DVD/VHS player that was crap. I bought another of theirs later that was a little better. I think it's basically a crap-shoot anymore, even with such names as Plextor. In an effort to keep costs down, they forgo the quality that made them a house-hold name.
I've been through 5 Plextor PX-716A's to date. The one I now have is the best, but it's not up to Plextor quality in my opinion. I find that they lack support for many medias that the PX-712A burned fine with at 12X. I have a PX-712A also. It's maybe the last-best drive Plextor made. The drive will only burn at 16X on a very few medias and doesn't really burn at 16X. There is a drop many times at the 4 gig mark. I've only found that Verbatim and True- Tayiou Uden (forgive me if I misspelled it) burn at 16X (but not really).
Will a firmware update fix the drive? We'll have to wait and see, but already the NEC 3500A and the BenQ 1620 Pro already outshine the Plextor by a wide margin, at least in my mind.
One more thing, Plextor must not like us here in America. We get a generic black faceplate without a logo and in Europe, the faceplate bears the proud Plextor logo.
So there you have it if anyone really cares.