Previously, I used to use MFC collection classes such CArray and CMap. After a while I switched to STL containers and have been using them for a while.
Can be used in STL algorithms which also have performance guarantees
Can be leveraged by third-party C++ libraries like Boost
Are standard, and likely to outlive proprietary solutions
Encourage generic programming of algorithms and data structures. If you write new algorithms and data structures that conform to STL you can leverage what STL already provides at no cost.