I currently have a no dash 4506 (hooked guard, Novak sights), and I carried a P220 for several years with the Dept. of Energy. Love them both.
Preference? The P220. I have large hands and the way I was trained to rack the slide and clear malfunctions is to put my large left hand over the slide. The 4506's slide mounted safety becomes an issue for me, as it gets in the way and in a vigorous action, the safety gets engaged.
Also, unless the 4506 was a LEO special order, it has the magazine disconnect safety, which I emphatically don't care for. I also think the Sig is a simpler firearm, design wise, so it breaking all the way down is less a headache for me than breaking a Smith 3rd Gen all the way down. I think the P220 is a bit more accurate out to 50 yards, as well. Lastly, the Smith really only has a few grip options...the slick factory Delrin grips or Hogue rubber or wooden grips, that's it. The Sig's have many, many grips options.
On the plus side for the S&W though, if you shoot really hot +P loads, the big heavy 4506 seems to keep the recoil down better, doesn't quite flip as much. It also has just a bit better 'pointability', if that makes sense.
Overall, I'd love to have one of those early 90's sharp-spur hammered P220's with the external extractor back, they were awesome. Maybe I'll snag one up one day. I know I won't sell my 4506 unless I have to do so to eat. It's a great 'for fun' range gun and as I've pointed out in other posts, it lets me get my inner Sonny Crockett on!
