The vocal positioning in Elliot Scheiner's 5.1 mixes is pretty consistent to my ears, it's definitely audible in all speakers as you say but significantly louder in the two fronts. From the sweet spot in all my surround systems (including the car), it sounds like center front and not the middle of the room. The vocal treatment on the new Pink Floyd Animals 5.1 remix is similar.Too much of the lead vocal in all channels, it's like ALL CH STEREO on an AVR. The instrument presentation is great, like much of the album, but the lead vocal seems too dispersed everywhere and loses focus. For me it sounds less like "surround" because of this.