Investment or pay and reduce loan amount in primary residence?

[Mabsl Koirala]

As interest rate is low and real estate value is going down, I am looking for investment property, rather than reducing my present loan amount. I am also refinancing my primary home to get low interest rate and go for 15 years, however monthly threshold could be double. My real estate agent is telling me to reduce the loan in my primary house, so I can get equity loan for any new opportunity. But my math is telling me its far better to go with investment property for now, as all in favorable conditions. Who cares for future as long as it is investment? Any thoughts and suggestions, more appreciated!