This is a very difficult review to write, I both enjoyed and disliked this treat all at the same time. From the standpoint of something that was pleasurable to eat these cups are fine. The milk chocolate is a very nice quality, the peanut butter is flavourful, and the texture of the pieces are fine. There's a nice balance of flavour and texture, in general it's a tasty treat.
The part that I disliked about these cups is all in the concept. It's as if Reese went one step too far by adding the Pieces. While it didn't ruin the treat, the advantages of adding them were pretty minimal. Unlike what the package shows, each bite did not reveal a bunch of colourful pieces in the cups. Since I don't have the ability to predict where each piece is in the cups, or the dexterity to bite at around them, I found myself biting through the pieces. This left me with the centers of the pieces (which is peanut butter just like the stuff surrounding it) with shards of the candy coating. Only on two bites did I actually see the colourful outside of any Pieces.
The slight crunchy texture wasn't bad, but nothing so impressive to really improve the bar. Basically, I found that these cups are an idea that might seem like fun, but after making one test version Reese must have seen how poorly it actually worked. I was interested in the idea of this bar, but after my first bite I realized it wasn't a good idea, even though it was a perfectly tasty treat.