Lon or others, I picked up a used Taboo MKIII a while back after keeping an eye out for a year.  I was looking mainly to use it as an headphone amp in my second system.  I recently set it up and tube/headphone rolled to find my sweet spot.  For now I have the ZMF Auteur OS headphones with French Dario Miniwatt E188cc , Telefunken 7189 pair and a Cryotone 5U4G(came with this rectifier).  For fun I hooked it up to my speakers (Fritz monitors) to compare it to my Raven Blackhawk Amp.  To my astonishment this Taboo just sounded better in every way.  The soundstage and realism just shinned.  It is now my second system 2 channel amp / headphone amp and my Raven Blackhawk and it’s tubes are now for sale.
Question…Is the Taboo MKIV a worthwhile step up in SQ from the MKIII?  Or is it just a different flavor?  Thanks