The Westin SCP is great. Rooms are nice, service is always perfect, room service food is good (plus Pinot restaurant downstairs) and platinum upgrades are reliable. Walking distance over a pedestrian bridge to south coast plaza. I stay here every couple months and feel like I'm coming home each time I return.
One tip. I prefer "park-side view" rooms. I find the view over the park to be serene and relaxing compared to the side of the hotel that faces the freeway and swimming pool.