Last week I went against all my principles and bought a high-quality DVD-Player without making a home audition to compare with my previous DVDP

. It was very cheap for me to buy but here is the result in short:
I now have a Denon DVD2800MkII (latest top-spec dedicated DVDP) retaling at £750-800 which AFAICS doesn't improve picture quality a bit compared to my 1,5 year old Sony DVP-CX860 300 disc DVD-Changer costing around £500.
So how come that £750 of dedicated high-performance state-of-the-art (or close, at least) electronica can't outperform my built-for-convenience Sony "converted CD-Changer" with presumably mediocre circuit design etc.
I'm using high-quality QED SQART RBG-only cabling for picture and Kimber DV-30 for digital audio. Visualisation is handled by a top-of-the-range (2 years ago) Philips 32" widescreen conventional CRT TV.
What am I doing wrong

[Edit]: The Denon DVD2800MkII recently won a comparison test in a reasonably respectable british magazine (Hi-Fi Choice) against such notabilities as Cyrus DVD 8, Roksan Kandy (or was it Caspian?) and Primare V25