I've been getting around 75% with the default compression setting (5) and am wondering if that is normal, since most test data I found pegged the number at closer to 60%. EAC + FLAC 1.1.2 used for ripping and encoding.

it all depends on what kind of music you try to compress.. presumably, atonal instruments take more space to compress, and generally, the more 'noise' there is in a recording (ie. the less predictable the sound), and the higher the SNR, the worse the compression.. if you want good compression, try encoding piano sonatas or something
you can't really make blanket statements about this across music genres, though.. it all depends on the instrumentation used