With all due respect, you have to listen to the things yourself. As the rankings within the range shows, the 840 is, technically, the superior amplifier. Whether you prefer it is an entirely different question and only you can answer that one.
If it helps, I had the 840C at the same time as a DacMagic. The former was clearly better in every respect though whether the additional expense is justified largely depends on the rest of your system and your own preferences. Personally, I would have put the difference towards better amplification or speakers and perhaps then I would consider the better player as the next upgrade.