I don't see either Dominate on the changed spell list, and dominate monster is 3 turns+1 per caster level. A turn is one minute. At the absolute minimum level someone can take dominate monster it lasts for 20 minutes. One cast lasts for 23 minutes at level 20.
Unless I missed something and the duration Was lowered, this is longer than: Any summon spell, undead or otherwise, any stat buff, true seeing, any weapon buff, magic vestement, magic fang, etc etc etc.
It's also Super Effective. No, you can't metamagic it, but thank goodness for that, since you can just recast it anyway and as long as this server uses a time-limited rest system you've got unlimited casts anyway.
Let me tell you, back Elsewhere I literally played enchanters for like 3/4s of my characters because the dominate spells+confusion were just that good. Cast dominate, turn invisible, run around killing things.
Heck, I play a character with animal empathy right now and let me tell you, that is easy mode.