In Mission-X case, I worked in integrating:
1. Latest FMOD API.
2. Latest XML Parser library.
In my own way I admit, I'm happy to integrate with the latest code, but it also means that there is compatibility issues that the simmer needs to be aware and address.
In away there is always a race between user expectation and programmer/development stability.
User - probably expects that application will always hold the latest code.
developer - prefer the stability of echo system and to know that when he/she compiles the code, no new issues will arrise.