Hi
I can only talk from my experience which is of one male dog who wasnt done. I was all for it - hubby against, so when I started to look into it I really couldnt be convinced of any health benefits. Sure there is a risk of cancer, but then whos to say that castrating them will insure that they wont get cancer.
Many people say it helps calm a dog down, Gunnar calmed down at two and Ive heard so many times people who had it done only to find out their dogs were still mental
As to having problems around bitches in season, I have to admit that when Gunnar was around 7 he did start to notice and could become a bit of a handfull - always wanting out to the park and did start to hump his toys. But it was only a couple of times a year for maybe two weeks at a time. I think actually that only happened after one particular bitch was let loose in the park at the time she was ready, before that he hadnt really taken any notice at all.
So for me I cant advise having it done. But it is a personal choice and Im sure you will get loads of advice from both sides of the fence.
Suki