I'm leaning towards doing the:

• SAN-LAX-LHR-FRA double connection on the outbound, since
  
  1. The times are good -- late afternoon departure from SAN is great, early evening arrival in FRA is acceptable (I can go to sleep not long after arrival)
  2. Less chance of weather delays (any history of problems in LHR at the end of Jan???)
  3. While the extra connection is inconvenient, and changing terminals in LHR is annoying, for me it's not as annoying as an early-morning flight
  4. I can upgrade to F
  
  
• FRA-ORD-SAN on the return, since
  
  1. The times are good (2 PM out of FRA is great, 9 PM arrival in SAN is OK)
  2. If I do get delayed in ORD, at least I won't miss my meeting
  3. While I can't upgrade since there is no F, I can survive in J
  4. Although, I do have a terminal change in ORD (arrive in 5, depart from 3)

Although I'm considering trying to do the SAN-DFW-FRA outbound, by skipping my morning routine (including shower and shave, which I can do the night before) -- just roll out of bed, get dressed, and head to the airport. Not sure my fellow passengers would appreciate it, though.