I actually compared all three (from the performance point of view) and I prefer objectdock, it's smooth and less ram-hoggish (although some people tell me different)
I found that the plus version of object dock has some cool features like the swivelling icon menu for example, but it loads so slow and runs too sluggish to be used efficiently. (even with my dual 3.6 and 4gb of ram O_o). I'd say this is because it sit's on the desktop and can't utilize the file system like explorer can.
And yes, the tabbed docks are fugly! Another thing that shits me is the inability to do much with the text that can be displayed on the docks...I want to get rid of that damn drop shadow!