I used to work with a guy who had a little carry out BBQ restaurant that he ran on the side; he made some of the best spare ribs I have ever eaten. His method was pretty much the way I cook mine, but for one exception. He told me that about half way through the smoking process, he took his ribs out and let them cool to about room temperature and then put them back in to finish them. He said this sealed the smoke flavor in. I have never had the patience to do this, but I think he knew what he was talking about. He also told me that he cooked large batches and froze them. The secret he said, after thawing, was to heat them up very slowly, and that way they retained their just-cooked taste and appearance and were not greasy, as ribs often are after reheating.