If you hit the ball hard and low on your return, you will probably get more errors or weak returns from the serving team, but you will usually make more errors yourself. You also have less time to get to net before the ball is returned at you.
If you hit the ball higher and slower, you will probably make fewer errors yourself, but will usually get fewer errors from the opponents. Keep in mind that a high deep return gives you a lot more time to run into the net before the server gets to hit the ball. If you’re tired, have bad knees or just have trouble moving into the net for any reason, you might want to try to use a higher deep return when possible.
Remember the number one goal mentioned above, if you’re having trouble doing what you would like with that tough serve and you’re trying to win, just put the ball in play no matter what! Pickleball is a sport where shot placement, steadiness, patience, and tactics have a far greater importance than brute power and strength.