I haven't ridden it from about Gaviota to Lompoc (although I've ridden 101 up to Buellton and then west to Lompoc), but the freeway sections are generally really good riding, as long as the shoulder is clean. There are very wide, paved shoulders. On a recent trip where everyone freaks out at the idea of riding bike on the freeway, I made it a point to see just how much room the traffic was leaving me. The right-lane traffic was leaving me anywhere from ten to sixteen feet. You won't have that luxury on a lazy two-lane country road! IOW, the freeway is much safer. I've driven (not ridden) the part of 1 from Lompoc to Gaviota, and although I don't think it was as wide as from Gaviota to Santa Barbara, I vaguely remember that there is still a lot of room for bikes except at narrow bridges; but there's not much traffic and you can time your crossings so they don't coincide with vehicles using the bridge and competing for the same room.
It's not hell at all from a traffic standpoint; but if you must ride north instead of south, the reason to go early would be to avoid the worst of the headwind. When we rode the other direction, we were going 30mph on the freeway, and in one place closer to Malibu, even 28mph climbing, because of the afternoon wind pushing us down the coast.