Never heard CA 840C but I have the overrated Dacmagic in my bedroom and I agree with your comment, harsh and artificial, on top of that I can't hear any differences between transports...I thought I was deaf!
Try the CDC-TL1 on it, it was night and day difference between my Oppo dvd and CDC into my Dacmagic (and the Dacmagic has a buffered de-jittering and re-clocking stage). The fluidity the TL1 gave, was a very nice combination with the Dacmagic I thought (the was no edginess at all).
Never heard the 840C, but it can now be had for $1.3k - so it's the wrong price point to compare anyway.
Bill, you seem to be suggesting that you'll be making comparisons of DVD+PDX, to your recollections of higher priced CDP's. Hmmm, that's abit flawed. You'd have to at least hunt out something with an impeccable reputation for the comparison to be in any way meaningful.