What a great place! Exactly as advertised. You are right in the middle, literally, of the theatre district. There are two pubs on the 1st floor (not noisy at all) and probably 50 more within 10 minutes walk.
This is small studio flat so its perfect for 1 or 2 people.
For groceries and eating in, scoot up to Tesco about 2 blocks away. But above all, insure you get an almond croissant and coffee for breakfast every day. Trafalgar Square and many other important sites are only 5-10 minute walk.
Picadilly line (subway) will take you from Heathrow to Leicester Square station. The flat is located about 1 minute walk from the tube station. In London, but not Paris, you can "tap in and tap out"- translation- just use your debit card at the entrance to tube and on your way out. No tickets, not special travel cards etc- basically a la carte.
Many great restaurants within 10 minute walk of the flat. Will definitely go back here.