Trying to decide on Marantz 5003

[snsguy]

I've PM'd a few people and they have suggested that I start a thread with my questions so here it is. I am looking at getting the SR5003 refurbished for $449 total. That is my price limit. I'm not a fan of the Onkyo's, sorry Onkyo fans, and I really have to stay at the price limit. I have Polk Monitor 60's as left and right and the CS2 center. I have an Onkyo sub and surrounds that came with my HTIB. The receiver from which I am replacing is a HT-R540. Eventually I want to upgrade the sub and surrounds also but I'm good on just the receiver for now. I am using the Panny 55 for blu-ray playback and I have Comcast DVR and and XBOX 360 component version not the HDMI. For my set up that I have now will the 5003 benefit me. I looked at the 4003 because of the Panny having analog out but I'm pretty sure that the decoders on the 5003 will be better than the Panny's. Am I wrong? I'm also a little concerned about not being able to use the tone or eq settings when HD decoding is in work. Right now I have to use higher treble and bass settings under the tone menu in my onkyo and I'm wondering if it will lack somewhere because I'm unable to use that. Or it just might be my Onkyo HT-R540 sucks. It's always caused issues like distortion and the center channel always being weak no matter what speaker I put there. Any help is appreciated.

SNSGUY