I've put my entire collection on my Mac PowerBook G4 and have the same experience. Not shuffling CDs is wonderful.
I also move favorite playlists to my iPod. I'm currently playing it through the car stereo with a poor cassette tape adapter. I've got a CD changer in the car, but I plan to buy an iPod adapter to provide a direct line-input to the car stereo for better sound quality. I've also bought Rush's 24/7 which includes automatically downloaded podcasts. It's great to hear him on the way to work in the morning. Our local AM station is pretty poor, so hearing Rush on the iPod is like being in the sound-booth with him. The sound is incredible.
Be sure to also buy a back hard disk in case your primary HD goes kablooey. I bought a Seagate 300 GB drive last week for $129 to back up my Mac. It's great peace-of-mind knowing I don't have to re-rip all my CDs.
I got an iPod for Christmas and it wasn't something I necessarily wanted. But once I started using it, I have found it indispensable. I especially love to use it for audio books and to use as a voice recorder with an iTalk.
I recently added the iTrip to my iPod. It plays through any FM receiver--car, home, etc.. We have a Bose Sound Dock for the iPods and a Bose Wave Radio and that darn iTrip makes the radio into a sound dock. Now I wish we hadn't wasted the $299.00 although the Sound Dock is a nifty little gadget as well.
The iTrip is fantastic!