I've used a Dewalt with the shadow for the blade line. The issue with that is that you have to start to lower the blade & have the blade guard lift out of the way before you can see it. This means you only have one hand free to move the wood. I see the Kapex 60 has slots in the guard, so can you easily line the cut up using the light without having to lower the saw etc?
According to this video, not at all. The shadow becomes clear only as you lower the blade until you almost touch the pencil line. Then only, there is contrast thus precision (IF you are actually looking at the shadow of a tooth and not the blade body which is recessed compared to the kerf of the cut).
Another problem I see with the shadow system is that you can't precisely line up with a pencil line that has been made on the side of a thick wood stock, since you won't be able to lower the blade until it close to the pencil line. Imagine using the shadow in the configuration you have at 5:00 in the video above.
I'm pretty sure the shadow thing is a serious step backwards compared to properly adjusted lasers (although the laser don't seem dead on in the video above). Festool may have switched to shadow 1/ because of cost and or 2/ to avoid trips to the service center just because misaligned laser.
I think the light should still be adjustable as it could very well be out of alignment with the plane of the blade. It's just that since you have to almost touch the line to get a reading it will be much less visible and problematic.