I would drop St. Ermin's & Marble Arch from the list, the former due to no lounge & the latter due to being more of a business hotel.
I personally prefer JW/Grosvenor House & w/ 72 suites better chance for an upgrade. Others like County Hall due to the Big Ben views. Others like Grosvenor Square due to its proximity to Oxford Street. You won't go wrong with either of the 3.
Have a great time. London in December is magical w/ the holiday decorations.
Regent Street Decorations
Cheers.