Carrying some power provides more effective carburetor heat and allows more precise adjustments of the approach including the rate of descent. It also keeps the engine temperatures warmer so that a more positive response from the engine will be available in a go-around situation.
Additionally, it increases alternator and vacuum pump output during the approach. Generally, 1300 to 1500 RPM will be enough to accomplish all of the above advantages.
A disadvantage of carrying some power through the approach until landing is that it will elongate the pattern slightly with the aircraft being on a wider base and having a longer final. Proper use of flaps is essential to avoid dragging the aircraft to the runway with power.
Use manufacturer’s recommendations when landing with your aircraft.