CDex settings

Hey all,

I've been experimenting with CDex and VBR MP3's and hoping someone can help point me in the right direction regarding what they consider the best settings that will give me the most quality for the least amount of space. --alt-preset standard is obviously the best but it takes up a lot of room and it seems like the presets have been tweaked to perform the best with those presets so messing with them may do more harm than good.

Also, can anyone explain to me how --alt-preset ABR works? When it reduces the bit rate in one part of the song does it use that space for another in hopes of keeping the file size similar to the Average Bit Rate you have set?

I've found a couple of guides that have helped but none of them explain how the program actually works and why the setting are being used.

I appreaciate any and all input.

Thanks

Jackson