DVDA background hissing

Why should this be a mistake?
I often place a lead instrument slightly off centre - it is a perfectly valid way to mix.
It also saves "room" in the mix to put the basic rhythm components down the middle.
Stereo is always a compromise. Whatever you do, it's un natural sounding, as you have to use EQ and reverb to simulate the placement and create the illusion of depth. It's exactly why I prefer mixing in Multichannel, as you use far less EQ (not so much stuff all fighting for the same space) and far less reverb (don't need to create the illusion of depth).

All I was saying, and I stand by this, is that with a well mixed 5.1 track using a true centre channel as opposed to a phantom one, is that it is EASY to tell the difference between a straight centre feed and a phantom one fed by L/R panned to the centre.
If in any doubt, track down those examples I gave earlier and listen to what is going on.
A centre pan still has sound coming from both L & R speakers, but a true centre does not. Move even slightly off centre, and you can spot it right off.