I have been ripping in lossless.... I presume this is 320 kps
No, 320kbs is the highest quality lossy (e.g. mp3, aac etc). If you rip to 320kbs and then burn that file back to a CD, the resulting file will be different from the original -- some information is lost.
True lossless is apple lossless (alac), FLAC (both of these reduce the file size, but if you burnt the files back to CD the resulting file would be exactly the same as the original assuming your initial rip was perfect). (It's the audio equivalent of a zip file)
The final option is to rip uncompressed (wav/aiff), in this case the files are the same as the CD but take up more storage space and sound identical to lossless.
320kbs is OK if you want to take the same files on a portable device, otherwise you might as well rip lossless unless you have a massive collection and a tiny hard disk drive. That said, 320 isn't a disaster, IMO it's very hard to tell it apart from lossless on most systems.