Complexes have really morphed for me recently. Two years ago, I would turn to complexes to work on conditioning, and quite honestly for aesthetic purposes. More work in a little bit of time meant that I was able to stay really lean. Today my complexes are shorter, with no eye on conditioning.
As I have gotten back into weightlifting more and more, the complexes I do today are about strength. Maximum weight for up to few reps. They provide a great opportunity to work on my weak points in the lifts, and on busy days provide the best bang for my buck.
My new strength complex focus should not make it sound like these are easy. They are still extremely hard, but for entirely different reasons than the marathon complexes I used to do.
Recently I put together 2 complexes that fit right in this mold. Strength based, ball busters. Check them out.