IME, and even with the same, or higher grit paper, the surface finish with the Fein, in corners where it's used, does not match the finish done with a ROS on the rest of the piece.
This can be particularly glaring/evident when using a light stain and it's why I make the last few grit passes with a finish sander that will sand into corners, instead of using the Fein.
(That said, and with furniture, I make a final, light pass by hand with the highest grit spec'd, regardless of the size of the project, breaking edges as I go. To me, that is the only satisfying part of the entire sanding process, and allows me time to inspect and rectify any problems with details).
Gotta get enjoyment out of sanding where you can ... ;)