Unveiled earlier this year, the Springfield Armory XD-S 9 mm 4.0 just happened to come into my office (because I just got it!)
Offering a 4-inch barrel to the 3.3-inch variant originally introduced, the 4.0 is only two ounces heavier and .7 inches longer than the original. Having had a chance to shoot both in a single range outing, I can honestly say that the .7 inches really do make a difference—so much so that I ordered the (slightly) larger and (very slightly) heavier 4.0 over the 3.3.
With two passive safeties (grip and trigger), accessory rail, and fiber optic front sight, the XD-S would be pretty well-kitted out to begin with. Add in the other accoutrements Springfield Armory includes with each firearm (holster, double-magazine pouch, two magazines, extra backstraps and a lock) and the XD-S—or any of the models available in the XD and XD(M) series—is a very sweet deal.
Look for a more thorough review of the XD-S 9 mm 4.0 in the July issue of Shooting Illustrated.