"Using nothing else but turn based buffs, Red Dragon gets AC 49 and average damage 22, with HP 400. When you also got the improved invisibility and Premonitions, the form's just powerful enough to make one unbeatable - only a top buffed cleric could beat that, or another same level mage with dispelling."
Actually, funny enough, I was attacked by a mage in tenser the other day, and I just stayed in human form and had high enough AC that in a short amount of time his tenser ran out. We were both stripped of buffs as well. I am pretty sure I could do that to any mage, and i know there's quite a few people with the same AC, clerics and fighters. Having low AC is never useful.