How's post-booking support from Ghaziabad builders?

₹80 lakh for a 2BHK in Raj Nagar Extension feels like a lot, but I'm just so fed up of renting. Finally taking the plunge, I'm comparing Gaurs and ATS for a flat there. I'm worried about construction quality – plaster cracks, seepage after a year, you know? Also, what's Mahagun's customer support like once you've booked? Heard horror stories about builders going silent post-booking. Someone told me to check RERA complaints for communication issues. Is that a real indicator? Any insights on these builders' actual construction quality or their post-booking support would be super helpful. Hope this helps someone else too.