kevin,
I am using a modded DPL projector with anamorphic lens - not exactly apples to apples to the sony, but pq differences related to sources should be relatively close. this might be a silly question, but do you see the same color shift from channel to channel if you plug that cable box...
the non-hd output from my dtc-100 is a very significant improvement over a regular composite cable signal into my pj. However, keep in mind that SD cable/satellite is never going to look as good as HD/DVD.
I would definitely recommend a directTV HD satellite box. HD-Net is simply awesome, HBO...