Does anyone use xs big dot sights on ther usp/uspc? I was looking into them and had a few questions. First I only seen the usp listed as a model will these also fit the usp compact models? Secondly do they make a big difference over stock usp style sights (which I like) when it comes to faster target acquisition in combat/self defense scenarios. I am getting my usp compact ready for dull time ccw use and was interested if these would be worth the purchase/installation. Thanks in advance for the assistance.