At the encoder configuration window, EAC presents a recommended setting from r3mix forum like this:
%l--alt-preset 128%l%h--alt-preset standard%h %s %d
Could anyone please give me a hand to indicate what's the advantage for this setting?

PS. You could test this fact via Exact Audio Copy, by a menu path like this
"EAC-->Configuration Wizard"

Looks like when you set "low quality" it uses --alt-preset 128 and when you set "high quality" it uses --alt-preset standard. Simply makes the things a little easier for newbies, but offers no better quality than these settings alone.