I have one, no cruise control already so can't help there

It boosts the voltage of mine to about 14.2-14.4 at startup and at warm at idle for a while it lowers to 13.5.

Not worth it unless you need it. An overdrive alternator pulley could give you extra voltage also.

 

I suppose I'll keep it in mind if I get excessive dimming after the Big 3. I appreciate all the comments everyone.