Just playing around on the website -- tried XML for a couple of properties in London.

The "Leisure Links" rate came back (~175 GBP), but every time there was also an "Escapes in Europe" rate that was about 30-40 GBP cheaper per night.

Neither one had any ID requirements lised.

OK - for definiteness, I checked out the Ren Chancery and Grosvenor House, dates in mid-January. See for yourself -- the numbers look pretty good.

[Edit] As luck would have it, some of the dates I picked at random were weekends. Still, 102 GBP per night at the Chancery is not too shabby.