As someone who has closely studied Spartan society around the time period of Thermopylae and the battle itself.
I can put aside the (major) historical inaccuracies and appreciate the beauty and unique techniques put into making this film.
If your someone who wouldn't like drastic inaccuracies of the history or the exaggeration of Spartan strength that has little to no mention of the other Greeks who were also present at the battle, I wouldn't recommend.
This film clearly focuses on the glory and power of being a Spartiate (leaving out the negatives), the virtue of the ultimate sacrifice.
But, the techniques put into the film itself really set it apart for me. I can ignore the inaccuracies and appreciate this film, it's uniqueness reminds me of the "other worldly scenes" from the film Gladiator.
I would rewatch