I've been using the neck/jaw index and shooting strong hand only in low light situations since I learned it more than a year ago. It works really well and has the advantage of being very versatile. You can use it equally well around cover on either side. For me it's a matter of my body not being built so that I can effectively use the Harries.

Some people criticize it because you're putting the light next to your head and "drawing" fire there. To that, I respond, look where the light is in relation to your body with either the Harries or Rogers techniques. ;)

You should be able to do more than one method to adapt to different situations.