Pennant Hills Road is a very busy road, but as always it depends how far the house is from the road, your need for access to transport etc. Turning in and out of such a busy road needs to be considered, probably only be able to turn left from your driveway and left into your driveway etc. Check if windows & doors etc are insulated for noise. There are some wonderful peel on / stick on noise reduction films for glass windows and doors these days. Short answer, if you have another choice, explore the other one before Pennant Hills Rd.