We were there last week and went from DL to Universal (past Hollywood) on Sunday morning (we left Anaheim around 10 a.m.). We are from Western Washington (an hour south of Seattle) and are used to quite a bit of traffic and we had a few slowdowns (stop and go) but then the traffic was light compared to the Seattle area.
We left Universal about 7 p.m. and stopped in Hollywood to check out the Walk of Fame and got back on the freeway about 8:30 p.m. and it was smooth sailing all the way back to DL.
We then left DL on Wednesday at 6:30 p.m. to drive to San Diego and we had no traffic problems. We then drove back to LAX on Saturday, leaving San Diego (Mission Bay/Beach area) at 9:30 a.m. and stopped at the Wild Animal Park on the way. We had no traffic problems and arrived at LAX around 3 p.m. It was raining that morning and I don't know if people in SoCal avoid the roads in the rain but that's a possibility--the amount of hype in the news for a few rain showers (they are called storms there) was humorous (again, we're from Western Washington and get rain frequently).