Can anyone tell me is there that much of a sound "upgrade" to go from the Superlux 668B to a set up Audio Technica AD900?  I want an open backed set for sound and I do like the sound sig of the Superluxes and actually bought them instead of a pair of Audio Technica AD700 that i was about ready...

Looking to get a set up cans mainly for gaming and movie watching (late night surround sound) and some music listening and have narrowed it to these 3 since the Fischer Audios (the newer light wood version) are avaliable again through Frogbeats.   Looking for large soundstage and positioning...

First off, I have only used cheaper IEM in the past.  I don't have alot of resources because of the new baby so I am hoping for help.  I have currently narrowed down my purchase list to Samson SR850, CAD Audio MH310, JVC HARX900 or the SuperLux HD668B (which i understand is just a rebranded...