Yes more effects. The Titanium supports EAX5, where as the Xtreme Audio only supports EAX4. More importantly, the Titanium has the full version of CMSS-3D that includes elevation and macroFx. Both these improve surround positioning in some games. Thirdly, the titanium supports Dolby Digital Live and DTS Connect, which allow you to have 5.1 gaming audio sent over optical to a receiver. Fourthly, the Xtreme audio is a software based card and offers no acceleration to gaming audio (although in practice framerate differences will negligible if you have a multi-core CPU.
The Xtreme Audio is, quite simply, an out of date card that is not worthy of the X-Fi name. The only benefit it offers over onboard is marginally better compatibility in a few more games. In fact, some motherboard audio now offers better features. The Xtreme Audio should, IMO, have never been released. It offers nothing that couldn't be done on an older Audigy SE card with a simple driver update (the SE is far inferior to the Audigy 2 or Audigy 4). It has no place in a modern PC and is one of the worst value for money soundcards on the market. Steer well clear!