I'm not sure the Torrance Marriott being near a large mall is better than an office park location

. Also, the MB Marriott sits on a 9-hole golf course, so if one's room is on that side a nice view (as well as being able to play the course/access to the golf club). The MB exec lounge is open daily. The TM is open for brekkie only on the weekends. Given both Torrance/MB Marriotts are close to good restaurants, on-site restaurants probably don't play a factor. MB Marriott is much closer to the freeways, as well as LAX. On-site self-parking is $8 more at MB than TM. I'm not sure what inferior physical plant means.
Let's face it - they're both biz hotels so not like a JW, but they're not Motel 6s either. So the bottom line is both TM & MBM are good choices if a FTer is in the South Bay.
Manhattan Beach Marriott (golf course side):
Cheers.