Most recently (2016), Mobile Fidelity have also released the mono mixes of Bringing It All Back Home and Highway 61 Revisited as limited-edition hybrid SACDs (Blonde On Blonde is so far curiously absent).  If you're really into hi-fi and already have an SACD player then these more recently remastered editions may be of interest; many serious listeners seem to prefer them for having a more natural, less tiring sound than the Sony editions. Even if you don't have an SACD player, you may find the sound of the standard CD layer slightly preferable.  The mixes are exactly the same, though.