Just opening this issue to have a counterpart to https://github.com/pydata/pandas/issues/9602 on rpy2's tracker.
Resume: pandas' own tools to convert pandas <-> R objects are deprecated, but, there are still some aspects where these functions work better that the current
pandas2ri functions in rpy2.
What is reported at the moment at the pandas issue (but there could be more):
- handling of NaNs
- index is not preserved in