FWIW, I have had a Range device on my car for about two years now and cannot imagine driving without it connected.
Every so often I have unplugged it just to remind myself of why it is there.
And then I plug it back in again as quickly as I can because I absolutely
hate the way the AFM works and makes the car feel.
As NBCamaro said, the lights aim at the floor and act more like a footwell light.
I don't even notice them any more.
Oh, and
no battery drain issues with mine either.
Way to
ruin a car just to gain a lousy mpg or so GM...!
As for the transmission shudder, like cellsafemode said, change your transmission oil before it's too late.
Do not postpone this.
I changed mine long ago, and so far so good.
It is a relatively simple DIY job and there are YouTube videos and writeups in this forum that will show you how to do it in great detail.