May I inquire as to why you have FLACs on the MBA?
First of all the FLAC vs 256 kbps difference isn't noticeable to most people, except in maybe classical music. Unless you're using high-grade audio equipment you won't hear a difference. I have used FLAC and ALAC files on and off, and really it isn't worth it for 99% of people.
If you plan on using the integrated speakers / sound card it's a 100% waste. Even with decent Bose headphones (INB4 Bose vs. Beats flame war) plugged in I rarely hear a difference in FLACs.
Not being rude here - I'm just trying to save you some space![]()
I encode my music using the LAME encoder. It produces VBR mp3 files that I cannot distinguish from AAC, FLAC, OGG, etc.