This is all speculation here since I don't have any CGFBMs, but I don't find serrations that useful on a knife that big, which I'd primarily be using as a chopper.
1. All that chopping might blow out (perhaps an incorrect term but I thought it would sound cool) the serrations.
2. All that chopping could have an effect on a plain edge, too, but I'll bet an INFI plain edge, even after hours and hours of getting beat up, could still handle what serrated edges are meant to do.
3. I don't find many situations where I'd be chopping and in need of a serrated edge. In general, I do chopping in the wilderness, while serrated edges are more for urban tasks, like cutting up rope or cardboard. Though you might need to cut rope in the wilderness, too, see #2
That's me. I only use my knives when I go out camping. Most importantly, since it sounds like you have both a CGFBM with and without serrations, which one have you found yourself using more?