As supine put it, it depends on your motion rhythm, but high tosses get tricky in windy conditions.
Another thing to bear in mind is that, when you're not too tall, if you want to serve hard you also need to put some side/top spin on the ball to make it drop inside the box, so you have to hit upwards and with good rackethead speed at the ball. If you hit a high toss, as well as your rackethead speed at contact point the ball is dropping faster that with a lower toss, which requires good timing. If on top of that you add windy conditions, as well as great timing you need to be a server with good variety, either to adjust your body positioning under the ball to execute the serve you intended, or to change your serve mid-swing by reference to the actual contact point.