I'm another huge fan of the Model 6906 in particular and the Smith line of "Third Generation" semi-autos in general. I carried one as a duty weapon for darn near two decades and the little Smith never failed to digest any round ever fed to it, including lousy agency reloads it had to endure during bi-annual re-qualifications. I'm now retired, but it remains one of my favorite pistols to carry concealed as a "civilian". I continue to trust the 6906 with my and my loved ones' life. What better endorsement can be offered?
People might complain of its trigger, sights, lack of compactness (due to the double stack mag), accuracy, general ergos and other perceived short-comings but you will seldom, if ever, hear of anyone knocking its superb record of reliability-and, imo, extreme reliability is by far the most important attribute any handgun used for self-defense can have.