The most important motivation for preferring std::list over std::vector is the validity of iterators, not performance. If at the time you're inserting or erasing, you have other iterators into the container, then you probably need std::list, since it insertion doesn't invalidate any iterators, and erasure only invalidates iterators to the element being erased. About the only time std::list will win on performance is when copy and assignment are extremely expensive, and in such cases, it's often a better choice to modify the contained class to reduce the cost of copy and assignment, rather than switching to std::list.
