I don't think you'll find such an example. XS compiles down to C code just like Inline::C does, so anything you can do in XS you can probably do in Inline::C too, if only by copying the generated XS C code! The critical difference is which one will be easier - XS makes some things easy (mapping complex C types into Perl and back) and Inline::C makes other things easy (writing new code in C).
-sam