i tend to push until i got 1 rep left around abouts. I also do drop sets where i set up the bar with kettlebells and smaller plates and take 5-10 kgs off and keep repping. I feel that used periodically it is actually good to push hard. I generally dont train with a spot so naturally will stop before i reach absolute failure anyway. Some powerlifting programs have quite easy beginnings to them where the %s are quite easy,my issue with those types of programs is that you can follow for 12 weeks or whatever and still not gain therefore wasting your time and effort. I prefer to put a bit of effort in from the get go and deload reasonably frequently. Sometimes due to work fatigue i have to anyway.