From my experience I have found a huge difference in various high end players I have tried in my system. Though as mentioned above the subtle changes don't make themselves noticeable instantly, its after a few days of listening to all of my favorites that I notice things missing or out of place or so dead on I wet myself. I am currently using a cheaper dac then normal(awaiting new cd player) and find it takes more then a few drinks to get enjoyment out of it, which gets expensive and isn't the best way to enjoy this hobby. I agree that a certain level of resolution is required to hear differences in players. The easiest test of a system for me(that is usually source related) is the first track of Eric Clapton's Unplugged CD, there should be a very real sounding triangle left of center to the rear of the soundstage and cheaper dacs, and low resolution system just don't make this seem to create this sound accuratly.
Whats the deal with CD players?
I have a hard time telling the difference between CD players, even ones that are cheaply made vs. 'hi-end', or even CD's vs. DVD players. I couldn't even notice a big difference between tube and solid state outputs. When i get a player home i'll set up a double blind a/b test vs. my inexpensive dvd player and have yet to find a player that i could honestly say was a marked improvement. When i read reviews, both amateur and professional, people make it seem like it's night and day. And what do people mean by jitter? Amps and speakers to me can be night and day, but Cd players? I currently use a pair of dynaudio 1.8's and some H/K separates and I'll admit I skimp on cables and use those plastic ones that came with my vcr and dvd player, but despite that, shouldn't I be able to at least tell which player i'm listening to? I'd upgrade my cables, but I don't think cables are to blame. I know this post will piss a lot of people off, but honestly, what is it that you hear that can make you drop tons of cash on a cd player?