I'm glad he's home and feeling better.
Ace is what is used sometimes as a "knockdown" drug. They have to get the dog out so they can intubate it, and then they use an inhalent anesthesia, such as isofluorane.
I generally request the "bag" my dog down. This involves a tech holding a big plastic funnel looking thingy over the dog's face so it breathes in the inhalent anesthesia and goes to sleep so they can intubate it.
It is the knockdown drugs that make your dog groggy and toddly after anesthesia.
Glad he's home and feeling better, and good for you for making the responsible choice and having him neutered.