Here's the unfortunate thing about this treat, you can't eat these peanut butter M&M's without comparing it to Reese's Pieces. It's a bit of an unfair comparison because they are different treats, but there are also some similarities that can’t be ignored. The difference between these two treats is in the chocolate, or the fact that Reese's Pieces don't have any chocolate at all. It's funny because whenever I eat Reese's Pieces, I always expect to find some chocolate between the shell and the peanut butter, and I'm always shocked when I don't. So now these M&M's give me that experience... well sort of.
The other difference I find with these, over Reese's Pieces, is the thickness of the shell. The shells on these peanut butter M&M's are much thinner than those found on Reese's Pieces. I would even go so far as to say that the shells on these M&M's are a little too thin. The chocolate layer is wonderful, and the peanut butter is tasty, but the shell basically disappears instantly once you put it in your mouth. I think a thicker shell could add something really interesting to this treat like a slight crunchy texture, but unfortunately, they fall short.
If given the choice between these or a bag of Reese’s Pieces, I think I'd still go for a bag of Reese's Pieces. I think I also prefer my M&M's with full peanuts, instead of peanut butter. It's not that these are bad, they're just not fantastic. They also have some pretty stiff competition with a classic treat.