HWY 1 winds along the coast and joins 101 at various locations. If and when you need to make up time hop on 101, for scenery take 1. If it's the old missions your after, most are on 101 but there are a few on 1 (Carmel, Bonaventura, San Luis Obispo, La Purisma .) It's the same deal with the wineries. With limited time, I'd stick with 1 unless you find yourself needing to book it to LA to catch your flight.