Hi, Billie.
Is the card you are referring to a rewritable memory card? I do not know of any method of moving the designs that would be faster other than a faster PC.
I am not familiar with CX other than reading their ad. It seems to be a very useful program.
I have other programs that I use and find it helpful to rename the designs so they are easy to recognize. From there I set up files for various categories (flowers, flags, horses, cars, etc). This makes it a little faster to find the designs.
An extra card can be useful, especially if the brand you are using doesn't hold but a few at a time.
It is also a good idea to back up the files in case of a PC malfunction. You can do this with a cd, flash drive (aka, thumb drive/flash stick/media stick) or a purchased program that back ups and stores all files and documents off site (something like Norton - there are others).
Best wishes and much fun with your machine embroidery.
Pattiann