First of all, this is a great location. I've been to HK three times and every time I've stayed in Causeway Bay. I must say, the room is very small and bare-bones. It's just a large bed and small table, then immediately to the bathroom. It might be hard to fit in two people, especially if you have a large suitcase. I did, which blocked half the floor space. But it's offset by the incredibly cheap price compared to other listings in Hong Kong Island.
The highlight is Lok Ling. She is a very good host, quick to answer messages and help with anything she can. At one point the shower flooded past the sliding doors (the shower head directly hits it and it may not have been tight enough to block the water). I told Lok Ling and she immediately apologized and let us use as many towels as necessary to clean everything up. I also accidentally left my jacket there and she said she and her son would mail it back to me in the U.S. She goes above and beyond as a host.
I'd recommend this listing, but mostly if you pack very light, don't mind a budget room, and intend to be out and about for most of the day.