Wow!~ You're getting a majorly high-powered machine! Good for you, Bawdy. I'm sure you'll put it through its paces--especially since you're one who prefers silence when you work out. You hve my admiration for that.

About the pad...since you have a carpet, the only consideration is whether or not you think the treadmill will ever be moved to some other spot in future, leaving the carpet under it exposed. In other words, do you care if the weight of the treadmill leaves permanent marks in the carpet or not? If you don't, then you need nothing else: the carpet should provide plenty of traction for safety.

Take care, Sona