This one tool has reduced the time it takes me to get a print ready for painting by 80%. The Dewalt 18V XR 125mm sander.
(Australian model https://products.dewalt.com.au/powertools/productdetails/catno/DCW210N/) I'm sure other bands would work just as well but as I already have a large set of Dewalt batteries it made sense for me to go with this one. This little unit with 80grit or 180grit paper can get a PLA print (yes it can be sanded if your careful) to a smooth finish in minutes. I use to spend hours sanding but the helm in the phot was done in an hour including the hand sanding for the details. Less time sanding means more time painting!
Saves heaps of time
nice even smooth finish on large areas
light weight and small
Still to large to get into the small detailed areas
Not the cheapest