I'm not an expert either, but reading those two data sheets there are differences in...
the package (28 pin vs 14 pin)
different sampling rates
capabilities (serial port, digitally controllable muting, etc.)
Wolfram states the less expensive one is for use in portable devices so I'd expect it to be less full featured. Again, just because there are differences among DAC doesn't mean they'd all be equally suitable in all applications. I'm looking to straddle two areas here hugh9269 and simply want to indicate that if a person is really serious in determining whether two players are the same or different, at the very least you've got to make sure your evaluation is both level matched and unsighted. If you can hear a consistent difference and that translates to a preference, more power to you. If not, then you should consider what other criteria are important and shop accordingly.
"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House