As a recent Coolpix 8700 owner, I have begun to compare Nikon-brand and other flashes. Since the vast majority of features on the Nikon flash units are not supported on the Coolpix 8700 (or other Coolpix bodies), it seems like a large cost premium is being paid for the high power Nikon speedlights (like the 800, 600, and SB-50DX) with no apparent benefit compared to buying a dedicated Nikon-compatible flash from Vivitar, Sunpak, etc.flash from Vivitar, Sunpak, etc. For example, the Vivitar 850AF is offered as a Nikon-compatible version (#59912) with a Guide Number of 120 (essentially the same as the Nikon SB800 guide number of 125), and weights about 13.5 ounces versus 12.3 ounces for the Nikon. The Vivitar sells for 3 versus well over 0 for the Nikon SB800. My basic question is: Is there any reason to prefer the Nikon brand, from either a features or performance stand-point? I have used Vivitar and other similar flashes before on older Nikon film cameras with excellent results, but maybe there is some advantage I am overlooking here which strongly recommends the Nikon flash solution for the Coolpix 8700 or other Coolpix models. Thanks for any advice or opinions. Larry