I'd say so yes. That doesn't necessarily mean a DG is the right choice. As you're buying the card for positional gaming audio. Some people prefer CMSS 3D, some prefer DH. Any comparison would be much better using a proper X-Fi. A Titanium would be a good buy if you can get hold of one.
I'd probably pick CMSS 3D over DH for gaming, if I had the choice. They are both good though in my opinion. Some people don't like DH though, as they find it can have an echo kind of effect. It's dependant on the user though, as not everyone finds this.
One thing that Creative X-Fi cards do better, and maybe one of the reasons why people find that DH has an echo to it; is that a macro means that any VOIP is not affected by the surround sound effect of CMSS 3D. With DH on Xonar's, anyone you are chatting to will have an echo sound to their voice. It's a little weird at first, but I soon got to used to it.
The SB Z cards don't use CMSS 3D. I think they use something called SBX Prostudio. How that compares I don't know.