I picked mine up at a gunshow almost 2 years ago -- so lightly used, it appeared as brand-new right out of the box (for an obscenely great price as it turned out -- $500)-- I now regard the 226 as the perfect platform for a service-sized pistol in .40 S&W.
I can speak only for my own .40 P-226, but it's been 100% stone-cold reliable with every possible brand and size of ammo, and it's a tackdriver to boot.
Long-term durability? Dunno yet (and don't really care), but I've shot the hell out of this thing, and no signs of possible trouble. I really, really think the .40 226 is a great pistol.
Hey, and you can get the .357 SIG conversion barrel, too ... and use the same mags.