CI recommendation

edit

I don't think there are enough people around here that have enough experience in all the listed CI solutions to give an objective answer to your question. Instead, use the following algorithm

bad_solutions = set()
while True:
    selected = pick_random_CI_solution_for_bitbucket(do_not_use=bad_solutions)
    if give_quick_test(selected) == "OK":
        continue_using_it_and_be_happy_until_it_breaks()
        bad_solutions.add(selected)

Basically, just pick one, and try it. If it works, keep it, else find a different one.