Pay down mortgage or put cash away for investing down payment?

[Scott H.]

I am trying to decide if I should pay double on my monthly mortgage amount on my residence to pay off my mortgage in 7-10 years OR put that additional money into a savings account to save up for a down payment on my first rental property. Thoughts? I would think it would be better to save up for the rental down payments. That way, once you had the rental property and, hopefully, some positive cash flow, you could couple that to pay down the mortgage on your residence faster?