Really enjoyed my stay at Marius's place! It had everything I needed for my week-long stay in Cape Town, and Marius was a remarkably attentive, communicative, and generous host. Very good coffee and food quite nearby (check-out, e.g., the excellent bagel place) . Overall, the area is a bit quieter than the most bustling areas in the CBD.
I would certainly stay here again and recommend it to others. One tip: There is street-noise at night, which I would imagine this is no different from the rest of downtown Cape Town. Plan accordingly, or rely on the disposable ear-plugs that Marius provides.