Original CD v/s CDR

Most of the times yes but cannot say that always the CDR copy is inferior to the original CD and what is wrong with it. It is like comparing two good CD players

EMI's copy controlled CD's always sounded better when extracted using EAC and copied on to CDR

Comparing different brands of CDR's I dont have enough experience.

Actually CDRs can sound better than CDs.
technically the stamping on CDs is done from a Glass Mother which can become less sharp byt then time it reaches the 4th stamping. these cds usuaaly are more jitter inducing in most systems.

using something like EAC to rip the cd via error correction and then writing into a CDR gives you a sharper cd..

well, since I instigated this topic in the other thread, I feel that I should contribute.

(1) yes, I can hear the diff between the original CD & the CD-R.
If the original CD is a well produced one, say, an XRCD (the very specific example I have is Art Blakey "Moanin'") then my CD-R is inferior. Not by much tho! I cannot tell if I listen to it in isolation. When I do an A/B, then the difference is apparent in the mid & lower bass. There is also a bit less shimmer in the high freq.
OTOH, if the original CD is a POS - the specific CD I have in mind is my copy of U2 "All That You Cannot Leave Behind", which I bought at Rhythm House in BOM & is a Dutch pressing - then my CD-R is much better sounding. On this U2 CD, my Scott Nixon non-OS DAC will *not* lock!! However, it will on the CD-R. whew!
Using higher quality blank CD-Rs, my copies of various Jazz, blues & rock CDs are very, very close.

(2) No, I cannot tell (so far) between 2 CD-R brands. From whatever I've read, it seems that the brands that I have tried are all peer brands of each other. I.E. I have not yet tried, what the audiophiles call, hi-end brands. They cost too much according to me! Maybe 1 day I shell out the money for them

Some of the premium CD burner I had mentioned in the other thread have the ability to burn deeper & longer pits (that are still within the redbook CD specs). This improves the sound (laser pick-up has an easier time reading the pit) & the bass response of that music. The bad part is that all the tracks from 1 CD will not fit on 1 blank CD-R.

Also, what I've seen is that the best results are obtained by burning "DAO" - Disk At Once - rather 1 track at a time. DAO is better 'cuz it gets the spinning motor up-to-speed once at the start & the motor remains at constant speed during the recording process (the data rate is varied as the laser moves from the inner groove to the outer).

You all might laugh at this one: using an after-market power cord + clean power to the CD-R unit + damping the chassis + rack isolation of the unit also enhance the reproduced sound. This is from my experience (but feel free to laugh if you so like. I did when the others told me this the 1st time! )

using something like EAC to rip the cd via error correction and then writing into a CDR gives you a sharper cd..

I can vouch for the Exact Audio Copy software. There is absolutely no difference between the copy and the master-CD, if you copy a master-CD in good condition using EAC. If you copy a scratched master-CD instead with EAC, there is infact an improvement in the quality of the copy over the master-CD.