After losing our beloved Daisy to anesthesia complications during a spaying procedure a few years ago we made the decision not to have our current dogs, (Autumn & Malibu) spayed.
During the past 3 years we haven’t had any overt difficulties with them, or noticed any undesirable behaviors that we would attribute to not having them spayed. (If anything the hormonal balance I strongly believe helps them be a lot more emotionally well adjusted.)
As an alternative to spaying/neutering, there’s also tubal ligation and vasectomies to consider, which will safely sterilize your pet without the hormonal and other health issues that come from tradition desexing. (Though I’ve heard it’s difficult to find vets willing to perform the procedures.)