I use it, it's not bad. You just use it like any other wax. The cleaner the surface the better the results. Don't put it on too thick it'll just be that much harder to take off and won't make much of a difference. As for layering not sure about it, I've put on multiple coats in a few months time frame but it doesn't layer like Zaino, it just looks like a fresh wax job.
Overall I like it. Gives good protection for a daily driver. If you are looking for a show car shine then stick with a polish like Zaino or equivalent.