In the end the overall execution is what counts. And for that you need to listen to it.
We did not want to spell out every change for many reasons and at the end it will invite all sorts of argument. You don't go to a high-end restaurant and demand that the chef tells you exactly what ingredients AND spices are in the food and how he cooks it! The chef is able to create those wonderful food not simply because of his overnight creation, but years of practice and experimentation. That's what you pay for.
We spent a lot of time on figuring out where and how to improve the sound (we have the advantage of better access to information than other companies who do their independent mod).
We are all about sound quality. We did made minor improvement on the L,R,C channels of the multi-channel output on the Nuforce Edition (the 2 channel section has the biggest improvement).
Correction: The SE and Nuforce Edition has no improvement over HDMI output.
Bottom line:
If you're a videophile and use HDMI, upgrading to SE gets you NO improvement.
If you're an audiophile and use the 2 channel as well as 7.1 analog out, then either SE or Nuforce Edition will be worth the price. If all you care is the 7.1 analog out, then it might not be worth the price to get the Nuforce Edition, the 83SE suits your need just fine.
If you want both a worldclass CDP and BD player, then run and get the NuForce Edition!