Noida builder delivery dates: The real truth

Since last year, I'm trying to finalize a flat in Noida, maybe Sector 150 or 137. Godrej, ATS, Gaursons... sabki delivery dates kaafi tight lagti hain. Kya inka actual on-time delivery track record sahi hai? Aur construction quality aur hidden charges ka kya scene hai? Sunna hai possession ke time bahut extra costs aate hain. Any experiences with these builders?