An Adjustable Rate Mortgage (ARM) is more popular with the borrowers. It offers lower refinance rates than fixed rate mortgage resulting in lower monthly payments. ARM is more beneficial when you move out of your house soon. With ARM, there is always a risk of increased rates and payments over the years. But you should keep ARM if the current interest rates are 1% lower than your ARM rate.
When the interest rates are very high, ARM may not be a suitable choice. With high interest rates, you save money with locked in interest rates instead of ARM. In converting your mortgage to ARM, you might end up spending more money.
A particular type of mortgage refinance rate does not suit every individual situation. One should also consider other factors like loan term besides the interest rate before selecting a particular quote. Your main aim should be getting the most suitable refinance and not just the lowest interest rate.