In terms of sound quality, I have only tested the Soundlinq SLI. I believe it sounds as good as playing a CD. In my Prius, I have the Sirius Sportster 4 plugged into the aux in from Toyota. It sounds pretty bad. It has a constant whine that only goes away by shutting off the power to the radio. Even if the satellite radio is off, it still makes the whine. The SLI also has a universal auxillary in. I'm going to rewire the Satellite radio to it to see if I can get rid of the whine. The Ipod sounds great. The SLI shows up as an auxillary multi-cd player on the screen. If you have the radio capable of playing mp3 disks, then the SLI will always show the name of the playlist you are using & the song you are currently playing. There are additional screens you can access in the Prius that will give you more info such as all the songs in your playlist which you can access directly. Toyota blocks these screens when you are moving. The Camry doesn't allow these additional screens due to some limitation to the radio. I also know that the SLI supports the paused playback when you receive an incoming call so you don't miss what you are listening to due to a call (especially helpful if you have audiobooks on your Ipod.) It does not allow you to use the controls on the Ipod. I didn't care about this feature because that was the main point to putting in the Ipod interface--so I wouldn't get into an accident searching for a song. The SLI is installed in both our cars so that the Ipods are out of sight. Everything is controlled from the steering wheel or screen.