We used to live in Cape Town and have been coming back every year since. We lived in Greenpoint, so we know the area well and we've even stayed in the Cascades building before, just in a different apartment.
If you're planning a longer stay, need quick access to coffee, restaurants and other shops, then you'll find this is an excellent location. It's just far away enough from Main Road to avoid all the traffic noise. There is quite a bit of construction going on in the area (as well as the building itself), but that is difficult to avoid in Cape Town. This has been going on for years as the popular areas are booming and Cape Town has lots of catching up to do in terms of renovations. That being said, the noise is always limited to day-time working hours and will have peace and quiet in the evening.
As I mentioned before, we've stayed at Cascade before, but we preferred Ilonja's place in the end because of the open design, which makes it feel more spacious. Check-in and check-out was super easy and totally focussed on making our lives easier.
And I should point out that we stayed here for 4 weeks and I had quite a bit of work to do. Good Wifi was absolutely crucial for me and is very often a major problem in Cape Town Airbnb's as many hosts rely on Mobile Data which is prohibitively expensive and thus rarely TRUELY uncapped. But in this case I never ran into any issues. Speeds were obviously not what you may be used to in Europe, but they were very good for local standards and more than enough for our needs.
So in short: As Cape Town "veterans", we can highly recommend staying at Ilonja's apartment :)