The advantage of the twohander is you can really drop the racquet head and accelerate the wrists upward for more brush. The problem sometime is having too much brush. You can also switch your top hand grip to a more SW grip and this allows you to have more upward leverage during your forward motion. This strenghtens your chances for excellent topspin as you go up through the ball.
Remember topspin is created from a low to high swing with a square racquet face on impact. Since the ball stays on the strings only for a very short time, the speed or glancing blow the racquet face puts on the ball is what allows a player to put more oir less topspin on the ball. Racquet head speed and upward movment determines the amount of spin on the ball.
Former USPTA Teaching Professional
Volkl Tour 10 V-Engine Mid/Luxilon Big Banger