Refi and pay off.. or hold and use mortgage write-offs??

[Brennan Utt]

Hi, 

I curreny have 10 rental properties and none of these loans are currently over $70,000 remaining. A few of these loans that are at 5.1 at 5.3% interest rates. As you know with today's low rates , I have the opportunity to take some equity out of my primary and do a cash-out refinance. I can then use this cash (120kish) to pay off some of the rental properties with the higher interest rates and get interest rate with the refinance at around 2.8  percent , if I do a 15-year. I  know some of the tax write-offs on mortgages help when it comes to tax time ( I use them, although I don't fully understand all the write offs) 

I did a Cash out refinance in 2016 on a 20-year loan  of 160 k  with a 3.99 rate and have 143 k and 16yrs left. What I was planning on doing is refinancing that loan to a 15-year possibly and taking out an additional $120,000 to pay off a few of the 60 to 70 k loans with a 5.1 to 5.3 rate rental properties. Wondering if it would be better to hold on to the 5.1 and 5.3 interst rate loans for another 28 years for a mortgage tax write-off purposes vs doing 15 year loan at a low rate. I'm not sure if the right offs on my big Cash out refinance will be as beneficial as my smaller 30-year loans.