Well, obviously with having a boy dog, I'm not gonna be much help here, lol.
But I wanted to add our family Golden Retriever (who passed in '04) got spayed later in life (but she was around 8 years old at the time) because of health issues that began to arise from NOT being spayed. The vet said we could have avoided these issues had she been spayed younger so while she was under for removing tumors, she also had an emergency spay. She came out of it GREAT and it bought her a few extra years of life when she was going downhill fast.
My dad's female Jack Russell got spayed around 1 year of age and it took a couple more months for her to "calm down" but I honestly don't know if that was because of the spay or just aging.
Good luck!
