I really find it indispensable for the Apple II... easiest way to grab files off the net by far. The downside is you need a (relatively) expensive ethernet card. The downside for a 68K mac version is that the machines that would benefit most (the 68000 compacts) all lack ethernet and EN/SC devices aren't exactly falling from the trees.
PPP is a bit of a non-starter too, since practically no one has dial up these days.