An interest-only payment on a loan is often lower than an interest and principal payment. If you want to ease up the impacts of rising rates on your cash flow and budget, paying an interest payment would be lighter on your pocket. Having said this, you must be conscious of how long you want to stick with interest-only payments and convert those back to principal and interest or pay more than the interest every month so you can still get ahead.
Advanceable mortgages on the street allow you to divide up a loan into interest-only (line of credit) and principal and interest loans at the time of application and then convert an interest-only loan at any point in time back to a mortgage.