It wasn't bad, although that explosion looked pretty underwhelming. My favorite part is the start when Irisviel drives around like a nut and Saber's reacting so funny.
And the Caster parts were not bad too.
The rest of the episode... umm, I guess we get more insight into Kotomine. And whatever the other guy was when he was bragging for his defenses.
Although this anime overall seems to have a bit too much posturing, and interestingly, I'd like to know more about Emiya; he isn't doing anything for me atm. Gilgamesh is kinda lol.
I give this episode a 6/10. It does its work as an in-between episode, but little else.