Here's my opinion:
There is a good chance that the Sony burner is really a rebadged LiteOn (although the CDSpeed quality test should have worked if that were actually true). LiteOn burners are notorious for producing marginal burns like this - particularly if you burn media that they don't like. That's why there are so many people in here who originally owned a LiteOn burner :a and then switched successfully to BenQ :iagree: .
I say that both burns are VERY marginal and some players will be able to read them (if they are very good readers) and some won't. Certainly the 1620 HATES the burns, since CDSpeed is counting PO Failures. I think your stand alone player must be a very good one if it is able to deal with either of those discs!
I'm certainly glad it's not me that owns that Sony burner :Z !