I have been using the X-Fi Titanium Fatal1ty Pro for a few weeks now, paired with my Logitech G51 5.1 Speakers and Logitech Noise-Canceling Headphones, and so far I have been impressed.
A majority of testing has been done with music, since I'm almost always listening to a playlist while working on the computer. I listened to a wide variety of music ranging from rock to rap and yes, even some country. Music in general sounds fantastic with this card, but as I mentioned earlier, enabling the X-Fi Crystalizer brings a whole new level of depth and clarity to the table. This feature alone would be enough for me to justify buying the card.
Using the X-Fi Titanium for gaming is where this card really shines. Set the audio mode to Game Mode, select the appropriate speaker configuration, and fire up your favorite game.
When using headphones or a set of stereo speakers, I would recommend enabling the X-Fi CMSS-3D feature (virtual surround) to get the most realistic environment possible. Games sounded absolutely fantastic when using this feature with my headphones. I was clearly able to hear enemies approaching from every angle which gave me a slight edge in Far Cry, as I could turn to meet them or even get the jump and surprise them.
My genre of choice is driving/racing games, so a bit of Need for Speed: Carbon was in order as well. Performance when using my 5.1 speaker system was equally pleasing and beneficial.
Additionally, this card comes with 64 MB of on-board memory (Creative calls it X-RAM), which can be used by a select number of games to improve overall system performance.
According to Creative's website: A game that detects X-RAM can decompress its data at load time so that it does not have to spend precious processor cycles decompressing data during runtime. This could also alleviate some strain on the hard drive, as game sounds could be stored on the card instead of having to stream them from the hard drive or RAM.
As of writing, I only know of a few games that currently support X-RAM, namely: Quake 4, Battlefield 2 and Unreal Tournament 3, but because I don't own any of them I couldn't test this feature out. It would have been nice for Creative to include one of these games as a bundle to show off the X-RAM capabilities, and encourage other developers to write code to enable this feature in their games.