I currently have an Onkyo 604 hooked up which I bought about 4 months ago. Today I just picked up the Denon AVR-987 because I was getting an amazing deal. Now I know the comparing the two by specs & features, the Denon is a better overall receiver. I know my 604 does HDMI 1.1 video only passthrough and the Denon does HDMI 1.1 switching. The Denon is also 110 watts per channel and the Onkyo only does 90; The Denon also has a bunch of more inputs than the Onyo. To be honest, I don't really care about that because I know that I will want a AVR that does HDMI 1.3 and that has atleast 3 HDMI inputs.
If I stay with the Onkyo and sell the Denon, I can make a couple of hundred bucks (will use towards a better video card), if I keep the Denon and sell the Onkyo, I'm most likely loosing a couple of dollars. I'm only 19 and I have bills to pay for!
My current setup (if it matters):
Samsung LN-T3253H
Onkyo TX-SR604
Mirage 7.1 Speaker System
Scientific Atlanta 4250HD
Philips DVP-5960
Sony Playstation 3: 80GB
Microsoft xBox 360: Halo Edition
Monster Power HTS-2600
Logitech Harmony 1000
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HTPC:
Intel Core 2 Duo E660
Gigabyte 965P-DS3
G.Skill 2GB
AuzenTech XPlosion 7.1 (Digital Optical Output)
Seagate 1TB HDD
nVidia GeForce 5200 FX (Working a better video card)
All connected with either HDMI, Digital Optical or Digital Coax.