Conventional Three Musketeers* never worked for me, because whipped chocolate is made of vaguely chocolate-flavored air. It's no wonder they're now heavily marketing the bar to women as a 'light' alternative (one that defies gravity, no less!), because women are always on the front line of marketing for anything that doesn't have a taste; it can be presumed to have lower calories. It was a smart move on the company's part to try to create new uses for the whipped chocolate, because it probably works better when combined with other ingredients than when used by itself as the sole centerpiece of a bar. The truffle crisp bar is, in design, also a much lighter version of the Twix, a smooth center enrobed in chocolate with a cookie base. Hold one stick of each and the difference is immediately apparent. Twixes are densewhile these bars are ephemeral, and sweeter because there's no caramel to get in the way of the sugary chocolate, plus less cookie. If you are a fan of super-sweet but less substantial, you could do worse.
*I notice they're using the numeral 3 rather than the word, now. How recent is that change?