For the record, as OP of this thread, it should be noted that I stayed at the Excelsior Gallia (see my review at
http://www.flyertalk.com/hotel-revie...ce-issues-1633).
It also should be noted that I wasn't terrible impressed by the PH Milan. It was surprisingly dated in all of its rooms and suites, and I detested the lobby space. Service seemed wonderful, which was a problem for me at the Gallia...but I'd choose the Gallia over the PH any day. Ironically, I'm writing this as I currently am at the PH Sydney.
I'd consider the FS Milan, which was a bit dated but of very high service standard, over the PH Milan any day. They both are in the central tourist area, which makes it icky to get Uber and taxis at certain times and even ickier to get out of the area due to such major traffic congestion issue.
I'd consider the Gallia again over the FS, however, because the Galla was so amazing. The service issues are a concern--since I'm so high maintenance--but those might yet be remedied since it's only been open a shorter time. But if using Milan as an entry point to Lake Como/Piedmont, the Gallia location across the street from the Central train station plus its incredible design make it the no-brainer IMO.