Interestingly enough what will work for you will not be all that similar to what works for anyone else
in some ways it is easier to respond to this type of question when poster is wanting to pursue a commercial goal. Budgets are always time as well as $ and a very significant reason for any commercial purchase can be to improve efficiency of the operation
generally speaking I would not recommend a creative card for any audio 'work', not for recording, editing or mixing. But if you are recording primarily, or exclusively, for your own entertainment and the creative card works for you . . . hey, don't change what aint broken. Inserting any new device or process into something as complex as an audio recording playback signal chain will almost always have unintended consequences. You can get the best piece of gear possible and spend six months troubling shooting artifacts in the system. Better speakers can and do highlight deficiencies in room and process.
More or less the same reasoning applies to using a hifi/home theater system to monitor production audio. The job of the hifi is to sound good, the job of production monitoring is to be 'accurate', very seldom are these the same thing.
But in recording the most important variable (after content and performance) for any music that is not completely electronic (tones generated electronically and listened to exclusive via headphones) is the room (followed by microphone and all other gear distant also rans) The problem with improving anything 'downstream' in an audio chain is that it invariably highlights, illustrates deficiencies 'upstream' Which does not mean you need to spend a half million buying a new building and then spending 6 million to renovate it for audio production before you can make perfectly acceptable music
it does mean that if you are content with the process and listening you have now that anything you change 'downstream' will probably not be a satisfactory one stop solution . . .
it is unlikely getting an audio card (don't consider anything branded creative to be 'audio' card) will produce significant improvement, if you are already OK with your final listening environment. If you listen exclusively on/in the hifi environment, changing to the KRK's in a typical basement is unlikely to produce significant improvement in the listening experience.
If your goal is to produce 'product' that has more consistent results across a broader range of listening environments that is a very different issue, whose most important variable (for anything that is going listened to anywhere but exclusively on headphones) is the 'room', in which it is recorded and room in which it is edited and mixed (with mixing environment being far more challenging then recording environment)
Main point is that, particularly if you are comfortable with your current listening experience no single thing you do is likely to improve, significantly, that experience. So? If you start making changes your at the very beginning of a very long, expensive path.
good luck
