Remember that both of these are marketing terms to describe a mastering process. Or, rather, they are shorthand descriptions. That something is mastered in 24 bits means little. (I suspect an awful lot of conventional CDs are recorded and mastered at 24 bits, and you know how good some of them sound.) JVC happens to do a great job mastering, which is why XRCDs typically sound so good. Other companies do quite credible jobs as well, and this comes down to personal preferences.
