I have squated to failure in the past. In fact I use to always go to failure on most moves. NOT ANY MORE!
My approach now is to lift just hard enough to stimulate the muscle, and be worked, but still have a rep or two left in the "tank" at the last rep of the sets.
I do as few moves as possible to hit all of my body. The goal being to do more X work per week, while not frying my CNS. I adopted this method after doing Oly lifting workouts, while lifting 5X a week.
I had used this Oly lifting program. I liked this plan a lot. I had some great workouts, and learned a lot on this plan.
Olympic Weightlifting Primer