3.1% for 30 year at 417K (primary residence) paying down balance by 15K to get to 417K, cost about 3K
3.5% for 30 year on investment property, cost $3500
Taking a variable rate of 1.65% on an investment property, cost $4800
Leaving one investment at 3.75% in case rates go lower
All in all will pay 3.06% with 80% at fixed rates for four properties.
Total savings will be 11K/year. so one year payback.
Using First Republic bank. They do have some other requirements like 10% of variable amount in checking acct but by an large manageable and seems well worth it. I had refinanced last year and thought that was the last go.