Is there a temperament difference?
As a general rule, males and females have different roles in feline society. A male's role is sexually driven so a fixed male lacks any real role and therefor has no competition. Even in the wild, groups of male lions, cheetahs, ect will work together in absence of a female. Understanding this helps us to understand why male cats tend to be more laid back and get along in groups rather well.
A female's role in feline society is not sexually driven. Even fixed females will still harbor strong maternal drives. Just observe a little girl playing with a doll to realize this. These strong maternal drives can create tension, the need to protect even from other cats. It is because of this that females make great companions for children and people but less so in multi-cat households. In nature, female cats can be very distrustful of other cats, especially other female cats, because of the incidence of kitten stealing. It is because of this that female cats will "bicker" and be territorial with each other.
Is there a size difference?
Testosterone does make the male Bengal larger in muscle mass than the female. Since Bengals do have a larger muscular build than other breeds, this size difference between the sexes is more notable in Bengals. However, fixed males don't retain the same muscle mass from Testosterone as unfixed males so the size difference between the sexes are not as great. Even males that have been used for breeding, once fixed, will loose a portion of their muscular build and become more comparable to fixed males. So here are how the weight compares:
Bengal male unfixed: 15-20 lbs
Bengal male fixed: 12-16 lbs
Bengal female fixed or unfixed: 10-15 lbs
Other breeds female or male, fixed or unfixed: 8-15 lbs