I don't use the symbol method, and I would be interested to know if it has any advantages over the way I do it.
1. Create the artwork for a single card, then select it all.
2. Use Effect -> Distort & Transform -> Transform..., and specify the horizontal displacement, and the number of copies required.
3. Use the same command again, okaying the warning about applying another instance, then set the vertical displacement and number of copies (I typically work in the top left corner, so my vertical displacement is a negative number).
I'd do it this way, because any editing of the original will propagate through all the copies, it is easy to use the Appearance palette to edit and adjust the instances of the Transform... command (which you can't do with the step and repeat), and the Expand command can be applied to turn it into a full page of artwork if needs be (if for example you need to do sheets with the names of multiple people).
Would the symbol method give a different result?
I'd certainly recommend the Transform... over step and repeat workflow (I find it incredibly useful for creating repeating patterns too - make a shape, apply the instances of Transform... as above, then apply any effect, warp or whathave you, and look for a pleasing result...).