No, no you haven't.
ALL other variables the same... only difference being COMPONENT + OPTICAL ....VERSUS.... HDMI
And yes, yes I have. I actually have two 360's in my place, I have a regular 20GB Pro, and my brother has an HDMI 60GB PRO...
In fact his in now hooked up in place of mine, in the exact same setup nothing changed... just recently since mine is at Microsoft being repaired for RROD.
I even A/B'd with the two options listed above.
kthnx.
nG