As @sajaysurya pointed out, we may not at all need xpandas for the core use cases.

This is a high-priority issue to be decided by w/c Feb 4 meeting, since it the data container is a central design decision. This thread is to collect pro/con until the decision is made - issue is complete once we decide to remain with, or leave xpandas as the data container solution for the API and implement the alternative (note: in the case of leave the issue is only complete once the alternative is implemented in the existing code).