Under-construction flat risks are just not worth it

Since January I've been shortlisting flats for my family, need a 3BHK. Arma Cavansite Phase 2 is ongoing, making me nervous about delays and interior costs. Winsomesk Mountain Crest looks cheaper upfront, but what's the total cost after stamp duty, registration, and fit-out? My wife's priority is a safe, ready home. Which has better schools/hospitals close by for the kids? Anyone have experience with either builder's actual delivery or hidden charges?