Advantage: Many lenders offer reduced interest rates for a limited time at the beginning of your loan, generally for periods between the first 6 to 24 months. This can provide a useful benefit for you, by freeing up some cash to help get your new home established.
Disadvantage: However, you should be aware that there is generally a catch with introductory rates. Usually after the end of the introductory period, when the rate returns to a variable rate, that rate will be higher than the normal variable rate offered by the lender. Therefore, you need to weigh up the pros and cons, to work out whether the benefit of a reduced rate at the beginning, is worth the additional cost of a higher rate later.