I take it from reading this entire thread that most people agree that yes the X-Fi is worth upgrading too if you are an audiophile, or are in the market for a new card. But otherwise if you have an audigy 2 or 4 or something like that. Then the answer is general seems to be no, its not worth the money yet. Would this be correct?
Would you upgrade to an X-Fi from the Audigy 2/4 because you are an "audiophile?" No, I don't think that's a good reason, by the same token I wouldn't vote for a Republican automatically just because (postulating here) I am a Republican.
I would upgrade to the X-Fi under specific conditions though (postulating again). Those conditions would include but not limited to:
1) Having an analog-only multimedia speaker set, because the X-Fi does not including 7.1 digital passthrough. (Although this isn't really a reason to upgrade if you had the A2/4s).
2) If I had speakers that weren't very accurate (say some $50 X-530s) and could benefit from the Crystalizer, because the added distortion is minor to the distortion the speaker already exhibits
3) If I had a large source of low bitrate mp3s (~128kbps) and don't figure to ever redownload them and thus use the Crystalizer as a "quick fix"; but may have to turn it off occasionally as the Crystalzer will overcompensate high frequencies on already compressed/bright recordings, and sound harsh.
4) If I wanted X-RAM functionality (particularly if I thought this might come into use later)--for the Platinums of course.
5) If I thought all those 10,000 MIPs did a better job resampling all sources to 48KHz than the Audigy 2/4, and I had a ton of money to spend and didn't care where it went. While this is a compromise anyway (who wants their sources resampled at such a low bitrate? It's gonna cause a lot of IMD distortion--real "upsampling" must occur at 2x the original frequency bandwidth to avoid IMD distortion). I suppose if you had a very resolving speaker you might hear the difference between "regular resampling artifacts" and "really bad resampling."
6) I really, really think EAX5 is cool, and need to upgrade from EAX4. Maybe those exaggerated echoes and room-transition-audio-mixing has improved. (To me this seems not that important, but maybe to you).
These are some of the reasons I can think of. "Audiophile" reasons might include better resampling, but the DACs aren't really any more resolving from the previous generations. For $20 you could pick up an outboard DAC that would put the X-Fi Platinums to shame.