There are really two different directions that candy companies go when it comes to candy variations. There's the unique and surprising direction, and then there's the obvious. This bar falls directly into the obvious category. It's not saying that the obvious is bad, it's just not that exciting or creative. No one is going to be shocked at the idea of combining milk chocolate with mint no matter what the texture of the bar.
Texture wise this is pretty much the same as the original flake bar, it falls apart in your mouth and then somehow clumps back together. This flaking then clumping texture was original when I first tried the original Flake bar, but it's not as exciting the second time around. Flavour wise it's a little different than the original, because of the mint. It's nice that the mint isn't super powerful, it accents the milk chocolate rather than dominating it. I don't think that the mint has improved the flavour, but it hasn't made it much worse either. The problem is that the Flake bar has normally had a really great chocolate flavour, so when you add mint, you're taking some of that away.
The best way to sum up this bar is to say that it's made a difference, it's a nice difference if you're only eating this bar once. If Cadbury announced that they were going to stop making the regular Flake bar and produce these as their replacement, you'd probably be very disappointed.