I went from the standard MCC +4 to the Midsize MCC +4 Align grips and although I'm sure it did alter the swing weight, I can't honestly say I've noticed a difference in how the clubhead feels in the backswing, although I will add I never have been super perceptive to things like feeling the clubhead in the backswing, feeling the differences between shafts, etc.
These guys wrote a book on it and have an app. I read the book. It was alright. I tried it, but it was hard to translate the rhythm to the course without the metronome. I preferred to keep my own rhythm with a song in my head.
Tour Tempo – Golf Swing Tempo Distance Training
We discussed it here.