Gurgaon downsizing: Under-construction vs ready-to-move, what's wise?

Since the kids moved out last year, I'm selling our big house and looking for a smaller, manageable flat in Gurgaon. I'm eyeing Sobha Crescent but it's under-construction, so delays ka dar hai. GTM Residency Tower is ready-to-move, which is good. What about the total cost of ownership, especially maintenance charges, for both? Also, investor ratio kaisa hai? Don't want to end up in a ghost society. Which one would you recommend for a peaceful, long-term stay?