there are some critical difference on some model. those difference are not easily spot on spec sheet.
although all receiver from $300 to $5000 can do 24bit/196KHz the chips used to decord are different. on lower end model, u may see Analog Device all purpose chip. on slightly better model, u will see Burr Brown 1791. some use more than 1 of the chip. However, on the high end model, you will see BurrBrown 1796. on Denon 5308, you will see total of Sixteen!! BB1796 chip!
the difference? 1796 has S/N ratio of 123dB, while 1791 only 110dB. 1796chip is at least 5 times more expensive than 1791.
on lower end model, one power transformer is used for audio. video, preamp, poweramp. On high end model, you will see troido transformer. On Onkyo, ONLY 905 is using troiod transformer.
video processing. on regular model, you will see idvdo or similier processer. on Denon 5308, it's Realta HQV. (the video processing broad alone cost few hundred dollars)