The recording industry's idea on dualdisc is more content will increase sales. At least two audio/HT mags have published warnings on DualDiscs. Also, there are stories out there of them getting stuck in slot load CD players(think your car) because of the non-standard thickness.
DualDiscs do not meet redbook guidelines and can damage your player.
Harman International has made it policy that DualDisc use voids the warranty. That means the following brands which fall under the Harman umbella have no warranty w/ DualDiscs Harman Kardon, JBL, Infinity, Revel, Audioaccess, Lexicon, Mark Levinson, Madrigal Imaging, and Proceed.
Other companies that have advisories against using DualDiscs while they study them include; Pioneer, Toshiba, Onkyo, Marantz(I'd assume this means Denon too as they have the same parent company), and Sony. In Sony's case their computer entertainment division said "some DualDisks may be unreadable on its Playstation consoles-----And it also warned that, for certain models, playing a DualDisc when the console is in a verticle position 'may damage the disc, the console, or both."
