Not sure if this is too late.....
Just had a couple of nights at CP Albert Embankment. Fairly central for walking, but 10 minutes from nearest tube station if you want to go further afield. Opened 4 weeks ago, a few minor (and not at all troublesome teething problems). Small hotel (77 rooms) and a very personal feel; I think they have more staff than rooms and they seem to care. Also, this could just be me (apologies), but for novelty value book a Club Room which comes with a Toto Washlet (not seen one of these in the UK before!).
Can't help but feel this should have been a Kimpton