As mentioned before on this blog, we use houserules for our ACW games. These rules have evolved over the years, and have focused on hex-gridded gaming mechanisms.
Recently, we tried to use these same rules in a setup using continuous movement and measurement. The conversion are of course quite easy to make (1 hex = 10cm), but surprisingly, some quirky effects came up: distance between units, terrain effects are now continuous rather than discretized, formations and footprint of units suddenly become more important, etc. Nothing too drastic, but still enough to turn the game into an altered experience.
Below are some (unedited) photographs of our game, based on the Command Challenge in Battlegames #32.