I bought a used Jet 16/32 oscillating version from somebody who hated it. There was a learning curve, but I have settled on 150 grit, and a light pass.
The scratch pattern is hard to remove, but it comes out nice and flat. I drop down to 100/120 grit on the ROS to get them out. I never use the oscillating feature, those seem even harder to remove.
For smaller parts I just take a swipe or two with a smoothing plane to remove the scratch pattern.