My chest day starts off inline, goes to flat, than decline, and than I finish it off with something like flies or crossovers. I personally find that incline and decline I feel the most, but I keep the flat in there just to keep every part of the pecs worked instead of just upper or lower. (If it is myth that incline and decline work different parts of your chest feel free to correct me, I heard that it does from a pro on youtube [it was either Jay or Ronnie I think])