[Morgoth the Great]

The Istari were more powerful in my opinion( [img]smilies/eek.gif[/img] Morgoth playing down Balrogs!) and this was shown in particular when Gandalf smote Durins Bane. The Istari also show their precidence in other places. They also have a lot more power within them than the Balrogs, for if i believe correctly, the Balrogs lost power when they were turned to balrgos, just as the orcs did when they were changed from Elves.