Ubuntu Tweaks in Unity has gone WAY down hill. I used it quite often in Ubuntu releases through 10.10. It was quite good. When I first tried it in Ubuntu 11 and 12, it had gone way down hill IMO. More than half its capability was stripped out. For housecleaning it uses Janitor (as I understand), which was a mediocre piece of crapola. I tried it in the pre-Unity days and it even destroyed my install once and I had to re-install Ubuntu from scratch. I tried to install an older Ubuntu tweak "tar" file I had downloaded a few releases back, but Unity kept coming back telling me it can't be installed because there is a newer release that must be installed.

BTW, I have Mint 12 installed (built on a Unity base - Ubuntu 11.04, I believe). After running a umber of updates, when I try to delete the "old kernel stuff", like all of 17, and some others, it just spins and spins and spins. After a couple of hours, I need to "Force" it to quit - I have "Force Quit" in a panel (with MATE and XFCE). So apparently, it needs a Sudo - even running it as the Administrator.