Done the trip from Phoenix to Sacramento a few times. There's really no easy way around LA without going a little out of your way. Of course, we stop at military campgrounds along our way. Last month, we made the trip but took our time a bit. It was actually not too stressful this time. We went I-10 from Phoenix to Seal Beach and stayed at SeaBreeze (Navy). A real nice military campground. From there, we took I-405 all the way up to US-99. I was surprised I-405 on a Tuesday around 10:00am wasn't that bad.
To us, there isn't much difference between US-99 and US-101. US-101 has more military campgroudns along the route. However, we usually take US-99 since it goes where we work for the summers.
Unless you have a reason to rush, take your time and enjoy the trip. This last trip, it took us almosta a month to get from Phoenix to Beale AFB. We can't comment on any other place to stay, since we always use military campgrounds, an Elks Club in Wasco, and sometimes an Escapee Park when making this trip.
