Flew with BTG Easy Click on Filter to reduce haze, improve contrast and protect the lens on the Spark. I deployed every multi-photo setting with no issues of gimbal overload. Quite satisfied for $11.00. Several other ND filters available by same company. Luckiamute River near my home in Oregon.
It depends if you want a polarizer, ND filters, or a dehazer. I ordered dehaze mostly to protect the gimble. I don’t want to be taking filters on and off since there is a chance of damaging it.