Suprelorin Implant for male dogs?

Hey pug lovers
Has anyone heard of or used the Suprelorin Implant?
I went to the vet yesterday to talk about neutering my baby and because I am not sure if it`s the right decision the vet suggested the Suprelorin Implant. It`s a chip they inject into the body which reduces the hormone level and lasts about 1/2-1 year depending on the dosage. As the vet said this is not a permanent solution, it only serves you to see how your dog will behave if he is neutered .
Spikey was a really friendly dog till recently , now he is really aggressive towards other male dogs and dominant. Two weeks ago he would stand by the door the whole day and cry to go out and when we went out he was crazy, running around sniffing and licking everything (there are a lot of female dogs around). This is the reason I considered neutering him (He will be 3 years old in May). My first and biggest concern is the anesthesia, he had the soft elongated palate surgery in September and luckily everything was fine but every surgery is a risk. My second concern is how will the neutering affect him meaning his cheerful character and everything that goes with it. Any thoughts? Every opinion is welcomed.