How do I call a comparison table only for the current category and subcategories?  It works if I use the autoadd feature in the admin controls, but if I just call the function in php code (so I can put it where I want it on the category archives page) it includes all categories.  I could specify the specific category, but I would like it to be dynamic like the one that is automatically added in.

It depends on what theme file you're editing and where in that theme file you're putting the function call.

Within a post loop, you can use something like get_the_category. In a category template, there's probably a global variable defined by WordPress for which category is being displayed, maybe you can look through the $GLOBALS array.

Here is what I did,

<?php $your_new_variable=get_query_var('cat'); ?>

<?php rs_comparison_table(5, '', $your_new_variable); ?>

Good luck!