I tried Unity a while back & vowed to give it a fair chance before claiming not to like it. I ended up thinking it's not better except for the Unity Launcher. I just think it's better to have the icons on teh left with an indication of how many instances of a certain app is open.
OK, so for a couple of reasons I ended up with Mate and I'm trying to get a dock on the left side of my right monitor (2 monitors), that will reserve space for iteself so that a maximized window doesn't continue under the dock.
First I tried Docky. It's pretty basic, but works well and reserves space correctly. I have a problem when moving a window from the right to left monitor. It stops about 2" from the left side of the left monitor.
So I tried Cairo Dock. Really flexible, can tweak all kinds of things to get it just how I want, except it doesn't reserve space. I think that works right with one monitor but not two (not entirely sure about that).
Next, AWN. Same issue as Cairo.
Last, Dockx. This one doesn't show in the "Add to Panel" list like it's supposed to. I can start it from the terminal and it seems to reserve space correctly, but I can't move it to the monitor on the right.
Does anyone else have one of these working this way with two monitors? My Mint 13 is a development install at this point so I've done all manner of tweaks to it & it's possible that it's not acting normally.