Yes. The spell makes you magically calm, so you can't get yourself worked up into a rage or frenzy. Your body just won't make enough adrenalin. For as long as the effect lasts, you're basically a fighter without bonus feats.
If someone is repeatedly casting the spell on you, at least you get a Will save to resist each casting. Eventually you'll roll a 20, be able to frenzy, and go chop the puny wizard's head off.
Entering a frenzy is voluntary. You do it when you want, not automatically when you encounter a mouse.
Ending a frenzy is the difficult part. You don't need a whole character with auras designed around that, though. A wand or two of calm emotions would be enough.
[Edited to add]
I don't know if it would be "op" because I can't figure out how to translate "op" into a noun or adjective.
From what I have read in the complete warrior, each time you take damage, you have to make a will check (10 or 15 + damage taken) not to go in frenzy agaisnt your will, therefore killing your allies if you can't end it and losing automatically one daily frenzy use each time.