I know this is not exactly about Trifield but the "in the band vs. in the audience" presentation of multichannel audio has been the subject of much previous discussion.

It's all down to preference with the musicians among us preferring to be on stage while the rest of us prefer the rears to add ambience. The only fly in the ointment is the propensity of producers to use all the channels in a gimmicky way to demonstrate just how "wonderful" MC can be.

On Trifield, there is no depth perception problem when correctly set up for the room. The amount of ambience on the rears is really quite modest in most circumstances so when people report massive improvements from rear upsampling I am very surprised. I can hardly detect consistent differences between HS=Y and N.

Malcolm