Builder promises are just marketing, right? Am I too cynical?

Since January I've been trying to pick a builder in Noida, ab samajh nahi aa raha. Amrapali ka naam suna hai, but their past... scary hai. Pride Group's Regal Residency looks good, but on-time delivery ka kya scene hai? Has anyone dealt with them? My parents keep saying construction quality is key, but honestly, I had no idea it's so difficult to check. Is it worth paying extra for a 'reputed' builder, ya sab same hi hai?