Thanks for the insightful answer. Lot of good practical information. Just what I was looking for. 8)From a scrictly shooting perspective, I like no VFG better. As a LEO, we do a lot more clearing/searching than we do shooting. Factor in varying thicknesses of body armor and clothing and the bulkier I get, the more I like the VFG.
I don't like lights with pressure/tape switches so light manipulation comes into the equation as well. With no VFG and the light mounted on the left side, above the rail, it was very very awkward to activate the light when shooting from the left shoulder. With the VFG and the light mounted on the right side, below the rail, the light could be easily activated from the left shoulder.
The two night fires made me reconsider the CAA FGA for a couple of reasons. First, it made the rifle more ambidextrous. Using the FGA, the light manipulation is the same for either shoulder. Second, light placement, especially with a 250 lumen light, became more critical. The barricades we were using were unpainted plywood. With the light in a Larue offset mount on the right side, I had to get further away from cover on the left side to make sure I didn't blind myself with my own light. Even with the dull, non reflective surface, it was suprising how easy it was to get a lot of light back in your face. With the FGA, the light is directly beneath the bore, so using cover is the same for the L or R side of the barricade. Even with the potential of a lot of splash back of light, I wouldn't go back to a lower intensity light. The ability to see more, at a greater distance is very important to me and worth the slight downside.
In the end, I would say it comes down to what best fits your needs based upon anticapted use and personal preference. If I didn't think I would use a lot of off hand shooting, I would probably run no VFG with the light on the left side above the rail. For the environment I work in, half the corners are left handed, so the more ambidextrous the rifle/light, the better, hence the reason the VFG is back on the gun.