ok so ive been getting these albums ripped into itunes that are 320kbps and its nice to know i have very high quality tracks... but this comes at a price 320kbps makes music files very very large size. a 4 minute song can be about 10mb in size. But on the other hand a 256kbps can take up around 8mb in size and 128kbps only takes up 4mb. It's not that im limited on space on my imac i have a 1tb drive, my issue is that i dont have a lot of room on my 16GB iPhone with videos and apps and all that good stuff. So i guess what i wanna know is am i gonna notice a huge quality difference on my ipod, car or computer if i were to convert all my 320's to 256? or if i took my 320's and 256's and converted them down to 128? I need a median between space and quality of tracks. If im not gonna notice any difference between 320 and 256 (or even between 128) im not gonna wanna waste storage. But if there is a noticeable quality difference if i were to play them in my car or on my computer i dont want them to sound like crap. If anyone can share there opinion on what i should do id very much appreciate it. Thanks. Oh and does the format make any quality difference? AAC or mp3?