Here's a call for testing for #xfce4-power-manager
, which is currently heading for its 1.6.0 release (which we can hopefully release in time for Xenial and include it), bumping it to new versions of several technologies (Gtk+3, gdbus and UPower 0.99).
The current git master version of the power manager is available at one of the team dev PPA's 
We're particularly interested in people with laptops trying it out, people charging phones and other peripherals - even more so people who've had issues with xfpm.
If you've not got that PPA installed
sudo apt-get install ppa-purge
sudo add-apt-repository ppa:xubuntu-dev/ppa
sudo apt-get update
sudo apt-get install xfce4-power-manager
There are newer packages of mousepad, parole, xfce4-settings and xubuntu-default-settings, if you want to try all of those out then rather than "apt-get install xfce4-power-manager" use
sudo apt-get dist-upgrade
That will upgrade all of those packages for you, if you want further
information on the dev ppa's we use for testing, check out the
contributor docs 
Try it out, if you want to revert to default packages run
sudo ppa-purge ppa:xubuntu-dev/ppa