Spaying/Neutering, do the benefits always outweigh the risks? (Not about pet overpopulation but for the dog)?

I know alot of people are going to disagree with me on this, but I would avoid spaying/neutering if you can. Especially if the dog is already an adult. Before my dog got spayed she was energetic and fun, but since I had it done she has put on weight and hardly ever wants to play. She just isn't the same dog. It probably wouldn't have been such a drastic change if I had had it done when she was little.