Or something else, yes. If the cost is potentially going to be big enough to convert for a large code base (keeping in mind testing might be a huge part of it - having to potentially re-test everything), and for very little benefit (well, unicode possibly, but it's not like Python 3's really any faster, and the GIL's still there), it makes you evaluate if it's worth enduring a bit more transition pain to convert to something else completely which would bring the possibility of new features / better speed.

It's also quite an issue for COTS software - sometimes to jump forwards and clean up APIs they have to do a huge refactor, sometime even a re-write of the API. If this is troublesome enough, it's worth taking the time to look into the competition.