Stuck between brochure and reality, need tips

Is anyone else fed up of renting? My landlord raised rent again, so I'm finally taking the plunge. Doing the EMI vs rent math, it just makes sense. I'm looking at Meenakshi High Life Towers, the brochure looks amazing with all the amenities and quality finishes. But I've heard stories, yaar. During site visits for under-construction flats, what are the hidden things to look for beyond just the show flat? Like, how do you really check for potential seepage issues or actual material quality that won't give trouble after a year? I'm talking about things that aren't obvious until you've lived there. Any tips on what to inspect closely, maybe even check in other completed blocks by the same builder? Hope this helps someone else too.