One key is to not add all their apps that they offer, some will really slow down the display of the toolbar. I took off the who.amung.us one for that reason. Mine is somewhat sparse until I can redo some of the icons today.
I have tried it but it seems too generic IMO. Sure you can add the default "add this to all these social networking sites" that you see on every other site but it really doesn't take advantage of vbulletins features. It would be nice to see one designed specifically for vb that includes PM's, latest posts, etc. maybe a summer project.