Looking to upgrade...

[volcomsocal]

I started a thread in the receiver section because I was looking into upgrading my receiver. I currently have 5 year old Sony HTiB HT-DDW670 that doesn't have HDMI. It's been working just fine ever since I bought it but I was looking into upgrading the receiver so I could get High-Def audio from my Blu-ray's. But one person mentioned it might be better to upgrade the speakers first rather than go with a new receiver. His reason was that I wouldn't be able to tell much of a difference between DD 5.1/DTS vs. Dolby TrueHD/DTS-HD Master Audio while watching Blu-rays if I were to upgrade my receiver.

So that's why I posted a thread in here. I was wondering how much of a difference could buying a good center channel make on my current HTiB setup? I was looking to spend no more than $500 on a receiver (Onkyo, Pioneer) but now I'm thinking maybe I should take that money, or at least part of that $500, and use it towards a good center channel. Thoughts? Ideas?