I have a Roland Quad-Capture card which I upgraded from a Creative Elite-Pro and I could hear a difference in quality. I'm considering the UCX currently but I'm now thinking based on what's being said here that I'm not going to hear a great deal of difference, unless it get down to having heaps of sounds in the mix. It seems that some of guys are saying that's where an interface like UCX comes into its own.
I also don't have studio monitors at this point...I have pretty good quality Polkaudio speakers but I still have no idea what to buy that will give me the clarity I guess I'm chasing. So many studio monitors, so costly and no way to really try before you buy...I guess it's trial and error.
Gaffpro, I'd be interested to see how you go with the UCX and those Dynaudios yet (they are the BM5A MkII model) monitors you were getting.