I am not planning on neutering Titan. I see no reason to, as I don't have intact females nor do I leave him outside unsupervised, so he would never be able to produce unwanted puppies. I've worked quickly to redirect any mounting and marking behaviors and don't have any issues with him at 11 months old.
That being said, I have neutered other giant breeds in the past in an uneducated attempt to alter behavior. Needless to say, it did not work. Loki marked and mounted excessively both before and after his neuter at 7 months old. He also became more dog aggressive after he was neutered, but that could entirely just be a maturity thing and not be hormone-related. Atlas marked obsessively and was still a horrendous resource guarder after his neuter at 1.5 years old.
People like quick fixes. If a puppy nips, cause it discomfort to stop it from nipping. If a puppy barks, squirt it in the face with water to stop it from barking. And if a dog mounts once or twice, remove its testicles to stop it from mounting. All three of those training methods *can* work and have worked for some people. However, the risk of fallout in all three situations is much higher than simply putting an appropriate training plan in place that relies on redirection and reinforcement, in my opinion.
Also, keep in mind that neutering *at any age* increases cancer risks (outside of testicular cancer, of course). The most drastic increase in risk is when the neuter is done pre-12 months, but there is an increase in cancer occurrence in all altered dogs, regardless of age of alter (shown by the all breed, Rottweiler and Viszla surveys). Also, neutering increases the risk of obesity, as many people don't realize that they should cut back calories post-neuter because the removal of testosterone from the system decreases muscle building and metabolic activities. So if you do decide to neuter, make sure to take a cup or a cup and a half off of whatever he's currently consuming!
Overall, I'm actually pro-neuter (at the appropriate age) for a vast majority of dog owners. I think most people aren't vigilant enough or responsible enough to prevent unwanted litters. However, I think you're perfectly capable of doing that, so that's when the advice becomes much more nuanced and it comes down to a personal choice and preference on your part.