The placement of the speakers sounds to be in the correct place. They should be to the sides and slightly behind of your seating position.

In a very well mixed 5.1 track, the directionality of the PSB speakers will not be noticed. Personally i found myself that I there are movies that I enjoyed where the ambient effect was not so ambient because the direct sound of one of my surround speakers did not match the sound that it was portraying. Did it ruin the movie? No.

The QS speakers by their design fire non direct. They send the sound out in a larger pattern and you tend to hear it as an 'all around you' type of sound. This is how the movies were like in the pre ATMOS sound system days.

An example.. one of my favourite movies was Big Trouble where they are at an airport and a large 747 flies overhead. If I am sitting in the left hand seat with directional speakers, the plane that should be directly overhead isn't because the sound from the left hand speaker is louder than the sound coming out of the right as your proximity to the speaker. However with the QS speakers, the sound is like the whole room and as the plane comes overhead and into the screen view and the sound moves to the front speakers, you get the feeling it was directly overhead.

I know that you would think that the sound should be just part of a Sub, but it isn't.

For some, the fine detail like this just doesn't matter. In respect to most films the direct sound can be forgiven. For me as I was buying all new speakers I went with the QS8 and really did enjoy them.. I am in the middle of rebuilding a permanent sound room and eagerly await to hear them to their full potential. But it comes down to that point of diminishing return. As you have said.. you really like your VP100 center channel speaker. Would a VP160 or VP180 sound better? Perhaps but the cost vs improvement might not be worth it for you.

Hope this helps.

Anthem: AVM60, Fosi DAC-Q5
Axiom: ADA1500, LFR1100 Actiive, QS8, EP500, M3, M3comp, M5