Hello!
My partner and I will be returning to tokyo for six nights at the end of May. Aside from the SL & MO we've considered the pen, park hyatt, and FS Marunouchi but ruled them out, though open to it if anyone could place a good argument

. Would anyone have a good comparison between the SL & MO?
Both the SL & MO are part of the visa signature hotel program, whereas the SL is not part of the amex FHR program. Do any of you have experience with what is considered a "room upgrade" and all the other said benefits?
Both hotels look like outstanding properties, what's important to us is customer service, location, quality of rooms, and spa/fitness.
Also, we will be arriving quite late into HND (22:30) and departing early (6:00). Are there public transport issues at these times? Hotel car is close to $400US and cabs $100+ each way...
Thanks for all your tips!