Nope, Megamanager is a programm, not a toolbar. When you got Megamanager installed, (and installed the add-on in firefox) everything you download with megauploads is automaticly downloaded in megamanager (in the background).
With megamanager I mostly download at al least 300 kb/s and sometimes more than 1 mb/s
also, when uploading files you can just select a number of files and they will upload one after another
