They seem to be decent pistols for the price. I fitted an adjustable rear sight on one owned by one of our folks a few years ago, and he uses it for a secondary weapon. He practices and shoots it more than the "average" cop does, and it's been a solid, reliable weapon for him.
Personally, I'd opt for the newer stainless version, simply for maintenance reasons ... but I already own a pre-railed 4513TSW.
The rail "wear" comment deserves some attention, however, but not because of the aluminum alloy used by S&W. We've seen some of our people apply lubricant either "too sparingly" (sometimes NONE), or else not properly ... which appears to have resulted in more visible "wear" to the top surfaces of the frame rails. It's created some really excessive wear in a couple pistols.
While it's fine to apply lubricant so the "inside", lower parts of the frame rails are lubricated, folks often forget that the "top" surfaces of the frame rails require lubricant ... The movement of the slide under recoil will create friction against the top of the frame rails, and forgetting to lubricate this top surface of the rails may help create excessive wear.
I've seen pistols which have had the "minimum number of qualification rounds" fired through them over the years exhibit much more visible frame rail wear than my current 6906, which has had more than 15,000 rounds fired through it.
Proper, reasonable lubrication will help prevent excessive frame wear ...