Media types are different, and will allow the writing in different formats yes, but the media format used for writing computer data is a completely different format to that for used for Audio.
I don't recall saying otherwise.
The discs that are commonly known as CDR`s are computer data discs, NOT audio discs.
There is no physical difference between the two Dave.
There are some specifically designed CDR Audio discs out there, but as yet, we have not compiled any data as to their suitability.
The only thing that is "special" about them is that they are designed for use in the standalone recorders that connect to a hi-fi.
"Normal" (I use that term very loosely) CD-R's won't work in the standalone units because they don't have the special header info pre-written that tells the standalone unit it can record to them (so you are forced to buy the overpriced discs).
As far as performance goes, readability comes down to how well the disc is made in the first place.
If you have a copy of the Red, Green or Orange books, I suggest to open them up, have a read and you will see.
Red book is just a standard for writing Audio CD Dave, nothing more, nothing less.
PS
Here ya go Dave, you can read it for yourself
http://en.wikipedia.org/wiki/Red_Book_(audio_CD_standard)