Since you're staying mid-week then, stay on the Westside (Santa Monica, vicinity). Why?
- If you're jonesin' to drive to go on a San Gabriel Mountain ride you'll miss traffic entirely because you'll be traveling in the opposite direction of traffic both going and returning. Traffic will be most likely a non-issue when you're traveling
from the West in the morning or
to the West in the evening.
- Easy access to the airport when you do, eventually, have to fly out. Way easier to make it from the Westside compared to the San Gabriel Valley area.
- Consistent mid-week early morning rides to get you warmed up, every day of the week except for Monday.
- Santa Monica Mountains... you can literally spend day(s) exploring the climbs in the area and most of them connect to each other, ridable from your hotel, no driving.
- Hollywood Hills & Bel Air have some variety to offer if you want to mix some steep climbs with ridiculously expensive homes and views of Los Angeles, ridable from your hotel.
- Everything post-ride is really nice out here. Neighborhoods in this area don't "go to sleep" at 19h.