There are several good threads on headfi.org, that might help you get the difference.
And one thing I have to add, I have done some A/Bing with different DAC's I have had for comparison with friends and family. I always like getting other opinions, because sometime you get too caught up in your listening.
Anyway the DAC Box S FL was preferred over the Schiit MB's 87% of the time. When comparing the FL to a Maverick upgraded Tube DAC, the Fl was running about 84% for. All levels matched of course.
Have yet to compare it to the Musette and DAC3. Not scientific, or a controlled study by any means, but interesting non the less to me. A total of 42 friends and family.
My obsession with filterless NOS for redbook is starting to wind down a little . Considering one can feed a clean signal with low jitter it does sound nice and pleasant with great low end and mids which is the kind of sound that you can just sit back and relax to, but you never experience that hair-raising sensation that an oversampling DAC can deliver. Modi Multibit, however, was giving too much of the latter at the expense of musicality and flow which I couldn't take. I recently got hold of a Parasound D/AC 1000 vintage DAC and it seems to strike the balance between NOS and the Modi OS type of sound just perfectly, very detailed and clean without being intrusive and harsh, definitely a keeper. On the desktop I'm currently using a Metrum Musette fed with 4x oversampled signal from JRiver which sounds very good. If you're using your DAC Box FL with a computer player that has a good resampler, i.e. JRiver or Foobar or better yet HQPlayer, try to resample to 88.2 or 96kHz/16bit, you may find it brings improvements in the treble while keeping the overall sound signature that you like so much more or less unchanged.