WT has been pretty decent for us (only TB level amount of data, so probably not as much as you folks are dealing with). The thing it has issues with is occasion

WT has been pretty decent for us (only TB level amount of data, so probably not as much as you folks are dealing with). The thing it has issues with is occasionally using the wrong indexes and caching them, and even putting hints in does not solve the issue in all cases. It started happening on WT, but it seems to be mongo's issue and not the storage engine.