Actually, the Su-27 family uses full-time flaperons and tailerons.

I've got video of an Su-27 going through the pre-flight control check and you can see the ailerons and tailerons operating in concert with each other. I'll post it a little later tonight.

I set up my Su-27IB to use both and other than reducing the throws a little, the model flew the same as it does with tailerons only or with ailerons/stabilators.

Dan