Nothing wrong with doing that on a feature branch after rebasing, as long as you are sure no-one else has pushed any changes to that branch in the meantime. Although personally i prefer --force-with-lease, which will warn you if that's happened.
If you have conflicts on a feature branch I guess you aren't the only one working on it and as soon as that's the case force pushing is generally a bad idea unless you coordinate carefully with the test of the team.
The only time I ever force push is on a feature branch that only I work on and I want to amend the commit I just pushed a second ago.