Not in my case. Material recorded at any speed on a +RW and played back on my Panny's either have X2, X4 or x10000?(whole 2hr disc in <5 seconds) scan rates. With +R's the have x2,x4 and x8? until finalized, after finalization they have all the normal visual scan rates. Everything is recorded on either a Panny ES15,25,30 or EZ-17 and played back on those, or a Sony DVD player. I have tried probably 2 different brand +R's and 2 different +RW's, and the 4 acted the same with regard to the scan rate. But scan rate aside I have no problems with + discs, expect none play on my ancient Apex player which I rarely use anymore. Oh and the Apex doesn't play -RW's either.
PatH-If I still had my 3575 I would probably be using + discs in it, since I believe + discs are more native to Philips, I believe they invented the + standard. And again once the +R discs have been finalized in my case anyway they have all the scan speeds, even on my Panny's.