Spring compressors are the safe way. You've heard the tales and most of them are true. Only way to check a spring is to remove it and measure it's uncompressed height and compare it to factory specs. If the front of your truck doesn't look level, you more than likely have a tired spring. But if you're going to have spring issues it will be the rear leafs. I've been in a car where a leaf spring snapped. Not an awesome experience. I was lucky I was only travelling at low speed coming out of a street corner. If it did that over a pothole or a drain, the car would've gotten badly messed up and me with it.