George.
Unfortunately I don't have the luxury of DSP5000s for rears,
so here are my comments upon the DSP33s.
I have DSP5000 L/C/R & DSP33 rears, (in a Type 6/'G' Layout).
They are fed a 598 through a 568.2, via MHR.
My rears are placed at a height of 1.6m from the floor to the DSP33 treble units. (approx' .75m higher than the L/C/R tweeters.)
They are vertically mounted on 'OmniMount 75 Series' brackets and each bracket is secured to the brick wall with 3 x 150 mm 'Rawl-anchors'. Each DSP33 is 'toed' to an angle of 21 degrees towards the listening position.
Imaging, width and depth of effects have a fine quality that is ideal for the smaller room and I feel that this works best, for me.
However, in a much larger room this layout may not suffice.
Hope this helps.
Holtz'.