I've had both the chocolate brownie and cookie dough versions of Quest Bars. Comparing the M'sM bars to Quest bars is pretty silly really. Sure, net carbs, sugar, and protein are similar, but Quest bars have far more fiber and far less sugar alcohols in general. For example, M'sM chocolate brownie has 7g fiber, 13g sugar alcohol. Quest chocolate brownie has 16g and 2g, respectively. And herein lies the problem I have with these bars.
The confectionery drops, the "chocolate chips", are straight sugar alcohols and they are gag-reflex inducingly sweet with a gross aftertaste. And that's just the chips. The bar is also super sweet. If you happen to be sensitive, digestion-wise, to sugar alcohols, these will have you running for the bathroom. It's just too much sweet without the need to have it there; Quest bars taste fine without the extra 11g of sugar alcohol. Atkins treat bars (the ones that are supposed to be like Snickers and Mounds) don't even taste this sweet and don't have a nasty aftertaste on their chocolate. The nice part about these chips is that they are pressed on the top of the bar, so you can easily pick them off and throw them away. Which only leaves the super sweet bar of dough or chocolate flavor behind to choke down. But at least they are kind of edible this way. Even coffee doesn't get the aftertaste out of your mouth! To be fair, the chocolate brownie doesn't have the odd aroma the Quest bar chocolate brownie does. Both the flavors of these M'sM bars taste like what they are supposed to taste like. But then again, so do Quest bars.
Other than the sugar alcohol issue, M'sM bars are not as chewy or dense, these bars are much softer. They honestly look smaller compared to a Quest bar. They are the same net weight, so I imagine the difference is made up in those chips that I keep dumping in the trash. My husband and I really like the chewy/dense texture of Quest bars (and the cookie-like bits in some of their flavors) because they make them feel substantial and satisfying as food on the go.
Maybe you like the sweet taste, or can't tell there's an aftertaste, or like that they aren't as dense/chewy, and that's cool. Your mileage may very, but I feel like I just wasted money I could have spent on Quest bars (that I have to purchase elsewhere) just to buy this one box to try them, hoping they'd be good for convenience sake. All in all, I won't buy these again and I definitely can't recommend them to anyone.