There have been a lot of threads on this that may be useful to you in getting different perspectives, so I would advise doing a forum search for old threads.
I agree temperament is the biggest factor. There are some generalizations that are usually made about male and female temperaments, but individual dogs vary a great deal and so I wouldn't let these generalizations dictate things. Females have a reputation for being more independent and maturing more quickly. Not as needy, and less easily distracted in training. Males have a reputation for maturing slowly, being more goofy, cuddly, and needy. I have always felt males are a bit more simple while females are often quite complicated in their feelings. But again, not all males and females follow these things.
Aside from temperament, there are some hormonal and physical differences that could sway you one way or the other. Males on average are larger than females and heavier boned. Spoos, as larger dogs, are recommended to be spayed or neutered late (if neutering is the plan) generally between 18-24 months and 12 months at the earliest. This means dealing with adolescent hormonal behavior. For males you may deal with marking and humping, both of which can require additional training to curb. I don't know about all males, but my own definitely went through a "gross teenager" phase in regard to frequent arousal, and I know this can be bothersome to some and is often cited as a reason for female preference. Females, on the other hand, will typically go through one or two heats before it is time to spay. For me this was not something I was prepared to deal with because my schedule is too unpredictable to be sure I would be able to be around for a heat cycle and I personally would not want to leave a dog with a sitter during this time. So that is why I had a male preference. If my life stops involving vital travel for work, then I would consider a female in the future. Both sexes have some minor additional dumb hormonal behavior as adolescents, but I don't think one is worse than the other.
Both can make very good family dogs. If you make sure you're getting a dog from a reputable breeder who will make a good temperament match, and you have your whole family on board for training, things should go pleasantly.