"Briefly, what are the pros and cons of pulling power to idle at the end of the downwind versus carrying some power through the final leg?" - Diana H.
“Carrying some power allows more precise adjustments of the approach, including the rate of descent. It also keeps 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 and provides more effective carburetor heat during the approach.
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.”