powerflex drives with or without filter

question.
powerflex 525 drives can be ordered with or without a filter.
I have always ordered and used the drives without the filter.
Which is really the best practice?
Thanks

The filters are mostly for compliance with the tighter EU standards for EMI/RFI emissions (as opposed to the less stringent FCC regulations we have to adhere to in the US). If you are an OEM building a machine that will end up over there, you need to order them with filters. If not, no need, unless you think you have particularly sensitive / unshielded electronic equipment in your panel.