Mini update, for anyone who cares:
I ended up buying this new receiver below, and connecting it with my old HTIAB speakers:
http://www.amazon.com/dp/B00CAAJDP6/...332200_TE_item
I can definitely say that, despite the old speakers, I absolutely notice a difference in sound quality on everything. Again, getting the HDMI ports, as well as a receiver that can read DTS HD & Dolby True HD, has certainly made a great improvement.
The question now is how & when I update my 6 speakers & subwoofer. I was THIS CLOSE to getting 3 new front speakers, but I didn't want to mix & match brands (as well as quality). So I'll probably replace all of them at the same time later in the year.
When I do, is it essentially just louder & clearer sound I'll be paying for? Thoughts?