Good: Fantastic Location. Center of London. Walking distance to west end and all the theaters. Restaurants and cafes everywhere. Great shopping nearby. Flat isn't huge, but is well designed. Easy to find. Checking in with the lockbox was a breeze. Had basic amenities (hairdryer, kettle, min fridge, microwave)
Bad: Furniture/mattress are the cheapest things you can get at IKEA. Mattress was so worn that my husband and I had to rotate it to get a good nights sleep (probably the first time anyone has ever done it). Couch was not very comfortable to sit on and the cushion slipped out the moment you sat on it.
Awful: Rattling bass from the salon below. Directly below the flat sits a very trendy salon. They start their music at about 9am and don't stop until 7pm. Bass it so loud that you can hear it through earplugs and it reverberates through the flat all day.
Overall: If you want a great location and don't mind staying on a cheap mattress/loud noise all day. It's fine.