I think that all depends on how close you approach true maxes in the gym. If you have a bunch of PR's that are very close to your true max then you are not going to make as much "progress" as you would if you always leave something in the tank. This is why you hear a lot of guys say that as well as the ever popular "don't miss a bleeping weight" and don't forget "save it for the meet". It's all about building confidence.
Another technique to use when you hit a wall is to dust off some old exercises you haven't done in awhile. Hopefully that serves the dual purpose of confidence building and strength building. If not then you should start program hoping like everyone else.....just kidding
Raw Elite Total at 308