One more time, and let's see if I can make this clear. One can do what one wants with the original recording. One can play it (but not in public), resell it, give it away, throw it away or rip it *for one's own personal use*. The one thing one can not do is keep the ripped copy of a CD or a track and then dispose of the original, or vice versa. It's neither legal or ethical to make copies of a CD, Redbook or otherwise (think "Enhanced" CDs), and sell them or give them away. Likewise. it's neither legal or ethical to make any kind of a copy of a recording and then sell or give away the original. Possession of the original is one's license for "fair-use" of the copy. If one doesn't have the original, one can't have a copy, no matter how one came by it.
It's not at all like selling or giving away a used bicycle. You haven't duplicated the bike. If one starts exactly duplicating the bike, and potentially violating associated patents and trademarks, and then giving away or selling the duplicates of the bike, you'll then have a similar situation, and a potential legal problem. It's the same with recordings. It is absolutely illegal and unethical to give away that burned duplicate of a CD. Playing the duplicate in your car makes no difference. You don't own the music on that duplicate CD to give away. The Grateful Dead can do what they want, but most people in the music industry aren't in the position or of the disposition to be so generous.
Copyright law can be bizarrely complex, and highly lawyered. But the basics are pretty straightforward, and fair to all.
BTW, whether or not a ripped copy of a CD sounds better/different/worse than the original will certainly have much to do with the format it's ripped to and then what hardware is used for playback. An mp3, especially at a low bit rate, played through some cheap USB arrangement won't sound nearly as good as a WAV file that is an exact duplicate of the original and then played through a high-end system.