I picked up the new HSU VTF-15H MK2 ($1006 delivered) - it replaced my 10 year old Velodyne HGS-15 Servo (which was 4x the cost) - and the HSU blows it away! It was like hearing a sub for the first time!
Shorty after I replaced my NHT T-6 Evolution (same age - $4k) with the EMP TEK R55Ti Evolution Towers and matching center & surrounds ($1700 for all five) - again the EMP TEK blow the NHT's out of the water! Soundstage and imaging are out of this world. The speakers simply disappear and all I hear is the music.
Same thing with electronics - with the old set up I had a Sunfire Theater Grand III - Marantz MA-700 monoblocks - expensive cables - blah blah blah. Today running a new Pioneer SC-85 Atmos receiver with the EMP TEK's - HSU sub and I've never had better sound. Period.