Some dogs don't drool at all. It is usually dogs with big, square muzzles that drool. I, myself, don't really mind the drool all that much, but I know their are those of you that get sick at the thought, so keep that in mind. Also you have to consider having a towel handy at all times to wipe the mouth, having drool everywhere in your house, and being prepared to get it on you at anytime. This means that the dog picks up commands quickly.
Males are generally bigger than females.
As far as personality goes, spayed and neutered dogs are more similar, but still not exactly the same. Altering eliminates many unpleasant characteristics of dogs. With females, they will go into heat for a couple weeks, twice a year. During this time, you will have all the male dogs in the neighborhood hot for her. Altered males are usually not as dominant and territorial as unaltered males.