Personally, with a caveat that I am a Londoner so I don’t typically stay in hotels in my own city, I would chose the Rosewood from all of the above.

Having said that, I don’t think the SL is in a bad location - in fact I would prefer it to some of the others mentioned.

Also do keep in mind that it is fairly easy to change lines (ok luggage may make that a bit more difficult) so I wouldn’t use that as a factor in my selection.

Lastly, every year most major London newspapers will run holiday specials of where to eat and the places that are open on Boxing Day. Quite a lot of places stay open these days. Check a few weeks in advance and you’ll find that you won’t be limited to Chinatown only.