I can not recommend this room enough. It's spacious and comfortable. It's about an 8 min walk to Pimlico tube station and 12 min to Victoria station. There's a supermarket nearby... To make a long story short, it has everything you need and is in the centre of London.
But definitely the best part are the hosts Carol and Alana. They are amazing: always ready to give advice/chat and are the friendliest, most open people you'll ever meet.
Trust me, you'll be hard pressed to find a better room...