The first generation of value series guns included only the 915 and 411. They did cut corners from the original line to save money, but still have a lot in common on the inside and outside. Non-Novak sights, less miling on the frame and a cheaper blue finish are the main differences.

Then the Assault Weapons Ban hit and the 915/411 went out of production. Smith & Wesson started producing polymer frame guns, which we all know by know are much cheaper to make.

Then the 908 came as part of the second value line (908, 909, 910, 410, 457) which is essentially stage two of reducing production costs as much as possible. This meant less milling on the slide and frame, no checkering or serrations on the frame, plastic sights and guide rods, etc. They are primarily distinguished by the blocky slide.

All said and done the value line guns are often not as pretty as the regular 3rd Gens, but their real "value" is in their functionality and often bargain prices.