The M457 is commonly considered by many folks to be a real sleeper in the defensive .45 ACP pistol market.
The engineering development and exhaustive testing that went into the 457's aluminum frame (carbon steel slide/aluminum frame) ... which was S&W's first aluminum .45 ACP pistol frame, the previous 4516-X pistols having had stainless steel frames ... revealed it to potentially be a real shooter's .45 ACP pistol.
One of the other guys at work has carried an early blued 457 for several years, and he's forgotten how many rounds he's fired through it. He likes to shoot a lot, though, and the well-used 457 was his back-up weapon for many years in a special enforcement unit.
Although I really like my original 4513TSW (6+1 model), if I were looking for another compact .45 ACP pistol I'd settle for a stainless 457S without any qualms whatsoever.
The TSW model is at least temporarily listed as being produced for Government - L/E sales at this time ... although there are probably some number of them floating around in the retail pipeline somewhere ... but it does offer a couple of advantages over the standard 457/457S series, such as the tighter toleranced Box-type frame & slides rails, loaded-chamber visual inspection port and delayed unlocking for reduced relt recoil.
The Value Line 457/457S does offer a lot of value for the money ...
The current 457 models use the same dual, 'nested', non-captured recoil springs as the 4013TSW, BTW. I've always preferred to replace my recoil and magazine springs a bit more often in my compact & subcompact S&W pistols, too.
Also, I've recently switched (back) to using one of the synthetic (NOT lithium-based) greases on my S&W pistols. There are a number of them out there, and using them generally requires (or, works best) if you make sure you've removed whatever cleaning solvent you've used on the surfaces to which you're going to apply the appropriate thin amount of synthetic grease. The folks at Mil-Comm Products recommend that you follow the application of cleaning solvents by wiping the parts with a cotton swab containing 90%+ isopropyl alcohol. This will remove solvent residue. Then, allow the parts to dry before applying the Mil-Comm TW25B synthetic grease.
I've also used the Ultima Lube grease from Wilson's, and have recently been trying some of the Shooter's Choice (red, easy to see) synthetic, too.
If you're interested in some if the benefits of some of the new synthetic greases, browse through this link about the Mil-Comm products, especailly their TW25B grease ...
http://www.jhllc.net/Merchant2/merchant.mv?Screen=CTGY&Store_Code=milcomm&Category_Code=data_tw25b
