I had a similar problem. After upgrading to Xubuntu 17.04, the mouse was too fast but settings had no effects. I solved this problem with xinput. See comments in this bug report (may be a duplicate):
https://bugs.launchpad.net/ubuntu/+source/unity-control- center/+bug/1683145 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1682193 Title: Mouse acceleration significantly reduced after upgrade to 17.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1682193/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs