The Razer card actually uses an OxygenHD chip by C-Media (the same one used by Auzentech on the X-Meridian). The Razer card was designed around their surround headphones (which as usual seem to be lackluster compared to a good pair of 2 channel phones).
I personally wouldn't recommend the Razer card for various reasons (proprietary port, it's gaming focus but the X-Fi still beats it since those cards can't do higher than is it EAX 2 or 3). I'm not a fan of Creative and am happy about the change to audio taking place in the computer realm (seems to be moving to a software focus which will give us a ton more options and we have plenty of processing power on hand anyways), so I really don't like recommending them either. So its kinda a stalemate here for me. With the X-Fi I'd recommend doing a direct analog connection to your reciever where your reciever acts as an amp and nothing else. This is the only way you'll get Creative's surround gaming capabilities. Well actually I'd recommend doing digital out as well if you listen to music or watch movies on your PC as your reciever should do a better job of handling it (and you won't have the X-Fi resampling your music). If you get the Razer then I'd say do the digital out and have the card encode it into Dolby Digital or DTS which your reciever will then decode. Since the encoding software anyways you could get away with a cheaper card (Bluegears sells a card with the same digital capabilities for about half the price). The problem here is that you lose the EAX stuff mostly, but you very well might prefer the sound anyways. This will hurt performance more than EAX on the Creative cards (so there will be a drop in framerates).
If you're just going to hook it up to the reciever then don't bother with the higher end cards. The Elite Pro's strengths will be mostly lost (really you'd only be taking advantage of the better DACs but they aren't that much better). You'll get pretty much the same out of the Bluegears card as you would the Razer so no need to spend twice as much on it.
You do have one last option as well. You could go with a Creative and then buy their DTS-610 external box which will then encode it into DTS. There is some latency involved and really I'd probably say just doing straight analog to the recieve would be better anyways, but it is an option.
So if gaming is the priority, I would probably recommend the an X-Fi XtremeMusic (or maybe the XtremeGamer and then you can do digital out to your reciever for music and movies) as they still have a pretty good stranglehold on gaming audio. For music and movies too then I'd probably say the Bluegears card would simplify things for you quite a bit.
If Vista is in your future then I'd actually say just stick with what you've got for now and wait for something else as gaming audio is a mess right now.
Oh, and sorry for being so wordy, hope it makes sense and is helpful.
I personally wouldn't recommend the Razer card for various reasons (proprietary port, it's gaming focus but the X-Fi still beats it since those cards can't do higher than is it EAX 2 or 3). I'm not a fan of Creative and am happy about the change to audio taking place in the computer realm (seems to be moving to a software focus which will give us a ton more options and we have plenty of processing power on hand anyways), so I really don't like recommending them either. So its kinda a stalemate here for me. With the X-Fi I'd recommend doing a direct analog connection to your reciever where your reciever acts as an amp and nothing else. This is the only way you'll get Creative's surround gaming capabilities. Well actually I'd recommend doing digital out as well if you listen to music or watch movies on your PC as your reciever should do a better job of handling it (and you won't have the X-Fi resampling your music). If you get the Razer then I'd say do the digital out and have the card encode it into Dolby Digital or DTS which your reciever will then decode. Since the encoding software anyways you could get away with a cheaper card (Bluegears sells a card with the same digital capabilities for about half the price). The problem here is that you lose the EAX stuff mostly, but you very well might prefer the sound anyways. This will hurt performance more than EAX on the Creative cards (so there will be a drop in framerates).
If you're just going to hook it up to the reciever then don't bother with the higher end cards. The Elite Pro's strengths will be mostly lost (really you'd only be taking advantage of the better DACs but they aren't that much better). You'll get pretty much the same out of the Bluegears card as you would the Razer so no need to spend twice as much on it.
You do have one last option as well. You could go with a Creative and then buy their DTS-610 external box which will then encode it into DTS. There is some latency involved and really I'd probably say just doing straight analog to the recieve would be better anyways, but it is an option.
So if gaming is the priority, I would probably recommend the an X-Fi XtremeMusic (or maybe the XtremeGamer and then you can do digital out to your reciever for music and movies) as they still have a pretty good stranglehold on gaming audio. For music and movies too then I'd probably say the Bluegears card would simplify things for you quite a bit.
If Vista is in your future then I'd actually say just stick with what you've got for now and wait for something else as gaming audio is a mess right now.
Oh, and sorry for being so wordy, hope it makes sense and is helpful.