My client was actually coming from Virgin Trains as well and we were both to stay in London for 1 night.
We were very happy staying at Mont Calm ( newly refurbished hotel ) and bcs city lounge being just accross the street made it even easier.
their website is http://www.bcscitylounge.com for more information. They have a corporate video that explains it all. I believe that’s ideal for business travellers in london …