Overall: would recommend. Good value for money with the location and secure parking space.
Location: Perfect for Waikiki. It's close to everything you need: shops, cafes, restaurants, and the beach. As others have mentioned, the area itself is quite noisy in the evening however we didn't really mind. Area generally felt safe and seems family friendly.
Apartment: The studio is a bit dated but fairly clean for what it is. On checking in, everything was tidy and we had all our necessities. The aircon worked fine but is quite noisy. Balcony isn't really kid friendly and probably wouldn't be suited to small children. The studio would suit a couple or a family with young children. For those with babies or toddlers that move around a lot, the mattress does sit quite high off the ground and the sofa bed probably wouldn't be safe for them either. You might want to consider bringing or asking for a portable travel cot (we brought our own).
Parking: fits SUVs, full size sedans, etc fine.