[Help] Is 6 months the best time to get my puppy neutered?

I have a male cockapoo puppy that will be 6 months old on April 28th. By word of mouth I had assumed that I should get him neutered at the 6 month mark, and at his vet visit today I discussed it with the Vet and he recommended waiting. He said that it would allow some more of the male trait to develop and also that early neutering increases the risk for obesity later in life. He also cited him being small (10.1 lbs) as a reason.

He then said that if he began to show signs of "marking" or lifting his leg that we should get him neutered right away. I informed the vet that he was actually doing this (outdoors only...thank god!) He then said that he would still wait, but didn't really indicate an actual time frame of when to do it. My puppy has become much more vocal (barking when he hears noises) and less obedient (not listening as well to commands) which i am attributing to this rise in Testosterone.

I did a little bit of research on the internet and i cant come to a good conclusion on what to do. Some articles cite the benefits of waiting and some say there are benefits to not waiting as well. Can anyone offer guidance? Thanks so much!