In the end, it comes down to preference. I usually drink an iced coffee with caramel and milk and I prefer Starbucks. Dunkin always makes it way too sweet while Starbucks feels like more of an average sweetness. The dilemma is that Starbucks is more expensive as it caters to a richer audience while Dunkin caters to a middle class one. Overall both stores have upsides, Dunkin Donuts' hot chocolate is really good while I hear that Starbucks' specialty drinks are (I've never had one). If I had to pick one though, it would probably be Starbucks.
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