I have collected S&W semi autos for a few years now. My first one was a 459 police trade in (from another country). I replaced all the springs in the gun. I sold my 5906 and kept the 459. The 459 was more reliable, but not quite as accurate. The 459 with the straight grip, and bigger sights, and 100% reliable, is the gun that feels the best in my hand and is my first choice for home defense. My CS9 is for concealed carry, but I picked the 459 above my 5906, and 4506 for home defense. I sold the 5906 and 4506, and kept the 459. Also I still have the model 39 that my Dad carried in the 80's when he was a Sherrif. I have chosen the 459 above my full sized 3rd generation S&W autos.