Kids moved out, now downsizing in Noida. Help!

Okay I'll be honest – I'm overwhelmed! Kids have moved out, don't need such a big place anymore. Thinking of a smaller flat in Noida. Has anyone had experience with resale value of flats by Godrej Properties vs ATS? Which ones are better maintained after a few years? Maintenance charges kitna hota hai, matlab? And should I be worried about hidden charges at possession with either of them? Honestly not sure where to start. Any advice?