If "achieving" your estimate included a lot of crunch, your estimate was bad. A lot of poor estimation externalizes it's error to those trying to meet the estimate. Long hours, weekends, etc. over months while pretending the work fit on a nice paced 40 hour week with breaks is not a good estimate. Chances are, there's probably a lot of corner cutting in the final product as well, because your requirement set and associated deadline was the priority vs having a quality product delivered.