The first part of 1 from Leggett is slow with 15MPH curves but otherwise OK in our 36' with toad. All of 1 in CA will be slow compared to 101. 46 to 5 is a good truck route but you might as well stay on 101 into LA just get there mid day.
Do NOT take 101 through SF. Take US 1/19th Ave (second right after GG) mid day using the left and then center lanes to 280. Have done that many times with the 36' and now 42' towing. Consider 280/85 to 101 or 17 to Santa Cruz.
101/68 to Monterey is good. Not everyone is comfortable on 1 south of Carmel.