CONFUSED....So...Who just upgraded???

[bklyn1028]

Sony KDS-R70XBR2, STB Scientific Atlanta 8300, Oppo DVd, PS3
Yamaha HTR-5150
OK,
Yamaha (7 or 8 years old) sounds terrific.
I have read that the tv has it's own video processor, but not the best.
Would like to get a HDMI av receiver, but, I have some thoughts.
1. Would the upscaling (upconverting) do anything for my current set-up, or is the tv I have giving all I'm gonna get. Which is excellent by the way. Nims Island on Blu-ray was absolutely unbelievable. Even impressed the wife.
2. I just watched Forbidden Kingdom, and noticed it had DTS HD MA...but I can't get that because of the optical connection, now...if I had a new receiver would getting that audio (via HDMI) be THAT much more noticeable.
I have yamaha speakers for surround and center , and Mission speakers for the front, so good speakers.
I could live with what I have (again the yammy sounds terrific) but am I missing out with the new audio tracks on blu ray.
Looking at Pioneer, Sony possibly Onkyo, Denon I have read gets hot.
Ok I guess what I'm getting at is remember when we first saw HD we all said....WOW!!....with DTS HD MA..will my ears have the same reaction....