Be sure to support the front of the bike before you take off the fork caps as it would drop as soon as you removed the fork caps. Also, make sure you measure the fork oil level to the proper specs, which should be included with your springs, on Progressives website or in the Vmax service manual.
One benefit would be a little quicker steering, the recommended lowering lengths are either by 1" or 2" using their lowering springs which require fork disassembly to install. If using the 2" drop make sure your forks are in stock position in the triple trees other wise dropping it more than 2" could have the front fender hitting the radiator.