3 stars for free chocolate.
I mean, the tour can be interesting and all (look, chocolate molds) but seriously, the reason you come here is for free chocolate.
It's a very short tour which starts in a gift shop, ends with a free chocolate sample and then the chocolate shop. However, if you are polite, you can often charm free samples from the women working the counter. I tried a whole bunch of the other chocolates before buying a small pack. One thing I loved was the lemon caramel, but I can't seem to find it anymore. Sigh.
It's not something you must do while in Vegas, but if you have the time, why not?