Lisa's flat in Marylebone is a fantastic location for spending multiple days in London. With easy access to the Baker Street tube stop, you can be anywhere in the city with relative ease. There are several shops and cafes, bars and restaurants within walking distance as well if you need something close.
The space is a good size for two people, and has plenty of natural light, and is well-equipped. As other reviews have mentioned, there is some noise from the street (as expected, it's a busy road). We were unfortunate enough to have some very loud upstairs neighbors about halfway into our stay, but this is in no way the fault of our host, and could happen anywhere. Overall we had a great time at Lisa's apartment, and I would highly recommend a stay here if you are visiting London.