Finally buying! But builders are driving me crazy

Okay I'll be honest – I work in real estate, but buying for myself is a different ballgame. Super area vs carpet area games are still on! I'm looking at projects by different builders in Noida. I know what builders don't tell you about hidden charges. I heard Jaypee adds a ton at possession. Anyone faced crazy EDC/IDC charges with them? Also, off the record, who actually hands over the RWA control after possession? Real stories, please!