
We have been having the same discussions here--i have 2 females already spayed at about 8 months-BUT we now have this guy boogeyman---he is on the larger size at 6 months. he keeps changing his head, his chest, his hind his legginess then he changes all over again! LOL...i have talked with several breeders and some have actually shown me pictures as to how their males developed from neutering from the same litter, 2 males, one neutered at 8 months and one neutered at 22 mos--HUGE difference and i do understand why. 
Same in the horse world- they do need testosterone to fully develope bone and muscle! But, boogeyman is also starting to feel his oats so to speak---the girls do put him in his place and if he would  start jumping our legs or oither dogs then he will get corrected just like if he was doing something else we would not like him to do. 
we will wait on this one- i am thinking right now that i will wait till at least after 18mos and then reevaluate his physique again--- In general---ALL of my dogs male and female have been neutered as pets and we have raised boxers too. The latest i generally neiter the males is 14 mos...but the frenchies breed seems slower to mature to me in general-especially potty training!! LOL
Just remember- Handling a male dog that is intact is not completely a pet---there is a difference between a stud dog and a neutered male...period--
attitude, machoism,territory-etc all come into play. as long as people are not oblivious and know how to handle their dogs around others and in public there is generally no issue.