Builder delivery timelines: real vs promised in Noida?

Okay I'll be honest – I'm selling my big house now that the kids have moved out. Looking for a manageable 2BHK in Noida. Has anyone had experience with actual possession dates vs promised dates with builders here? Specifically, is there any difference between the big names like Godrej and ATS in terms of on-time delivery? Don't want to get stuck paying rent AND EMIs. Kya kisi ko pata hai about hidden charges cropping up at possession too? That's my biggest fear, honestly.