Receiver Help
I'm not quite I understood correctly your question, but I think that if you are happy with the picture and sound of your Panasonic HTIB then that is all that matters.
These forums are great for many of us, myself included. But in the end, it's you that makes the final decision. If what you have serves your needs and you are happy with the performance then that is what matters.
With that said, a good receiver will have more input, outputs then a typical HTIB solution. You will usually get higher quality DAC in a receiver as well as better digital processing. Also, most HTIB have a high THD of 10% where a receiver may have anywhere from .03% to .07%. You will notice this when you are close to the speakers and hear a hiss/noise coming through them.
Hope this helps somewhat.