CAF files address a file‑size limitation (and thus maximum recording length) of WAV and AIFF, by allowing recording lengths of up to 13 hours and 30 minutes at 16‑bit/44.1 kHz.Macs are generally happy with WAVs, so it makes sense to use this format if you're going to be platform swapping.
Some prefer the results with no dither applied at all! The only way you can decide which one you prefer is to do some critical listening tests, bearing in mind that the efficacy of the different types will vary with the kind of audio you're truncating. Logic offers a few dither types, including Apogee's well‑regarded UV22HR, and you'll find much discussion on the Internet over which one is best. Dither works by adding noise to the audio in a clever way that minimises the effects of quantisation error when you reduce word length, and should only be used if you're bouncing down to 16‑bit for the final version of your mix. The only parameter here that you might not find in more conventional CD‑burning programs is Dither. There's also a simulation mode, which can be useful if you want to check the veracity of the output and reduce the possibility of producing coasters. Here you can select the device you want to use to create the CD and the speed of the burn. Confusingly, this feature is buried in the File menu's Bounce window. If all you need to do is to drop your current mix onto a CD, Logic Pro has the ability to burn an audio CD or DVD‑A (for high bit/sample rates) directly from the program. Logic's capabilities in the export and output department have come along in leaps and bounds over the years, and Logic Pro 9, in particular, addresses many of the requirements (and irritations) that users of the program have been asking Apple to address for some time. Things are more complicated now: you may want to a create a stereo file suitable for sending to a mastering engineer, to pop off to MySpace, or to import into a video editing package such as Apple's Final Cut Pro. When you had completed your magnum opus in Logic, all you needed to do was export the stereo mix to a file and burn it onto CD.
It was so simple in the good old days - or the 1980s, as we call them. For every destination you might have for your mix, there's a correct audio output format.