ok apart from the lack of mainstream music available in lossless formats to download....
There are few mp3 players that will play them
The ones that do play them see a much shorter battery life through playing them
There are few mp3 players available that store more than 60GB and thus you might start running out of space
The difference between a GOOD mp3 (encoded at a high bitrate) and a FLAC file is mostly placebo (I did some blind testing at the weekend on my hifi (NAD C352 amp, NAD C542 CD player, JMLabs Focal Chorus S speakers) and I really struggled to hear a difference.
fini