There is no quality loss at transcoding process between any lossless formats, and you always keep the original quality intact for lossless->lossy unless you threw away lossless files after transcoding.
This also means you can also get exact copy of CD if desired, and there is no degradation occurs if the file has to be edited sonically.
Not to mention, generally lossless codecs handle high-resolution better than lossy codecs.
And there are other tiny advantages such as multi-channel support, but they are not that important to be mentioned.
Only disadvantage is the hard drive space, which is non-issue when you can get 2tb hdd for about 70 bucks now. Also notice even your portable player (Sansa Clip+) supports lossless files.