Can be much longer than a santoku(up to 360mm)
Always has a pointed tip which can prove useful for a number of things
Slightly curved profile that's nice for slicing and rock chopping
Never bigger than 7 inches
Flat profile which allows it to connect with the board completely, making it easier to make clean cuts of vegetables. Not suitable for rock chopping
Can have a slight point or completely rounded tip(usually found in more western made Santoku)
Often much cheaper than an equivalent gyuto
Easier to find with a granton edge than gyuto, if that's your thing.
Those are most of the traits of both I can think of off the top of my head...People with smaller hands tend to favor the Santoku but neither is necessarily a bad choice, its mostly preference and what you like.