[akhtene]

I agree that Balrogs are more powerful than dragons. A dragon's weakness is its 'material' body, that can be damaged or destroyed. Remember how a common archer killed Smaug the Terrible with just one arrow. And their magic, perilous to mortals, was, imho, akin to hypnosis mordern reptiles are said to possess.
Balrogs were the Mayar, fiery spirits, clad on flame and darkness. It took Gandalf 10 days to do away with one. Quite enduring was it (he??)