As Ron said, TeraStation & LinkStation have the same hardware, as have LinkStation & Buffalo. No wonder since they’re all produced by Buffalo, why should they develop more than one embedded platform with nearly the same specs 😉 So I’m running it on the Kurobox with above performance.
Whether its on the same decoder depends. Firefly is imho using an external one, which means that you can now easily replace flac 1.1.3 with 1.1.4 and gain their speed improvements. flac is available in source as well though, if Twonky maybe did compile directly with flac 1.1.0 and never updated that to newer versions, instead of using an external library, that would qualify for some quite slower speed (I do not intend to say they do, just that this is the only circumstance I could image, other than some really creepy code around for streaming, which I can’t image much less… only Slimserver is that bad that it has a multiply-by-30 factor 😀 ).