Iced Coffee: Dunkin Donuts vs. Starbucks

I am conducting an experiment this week. I am taste testing iced coffee. This lies at the core of my hypothesis that coffee's diuretic effects can help counteract naturally-ocurring swelling and water retention. Since this is the hottest week this year, this will help me test said hypothesis. As a happy result (or koikidenke ;P) I get to taste-test a few iced coffee drinks this week.

My first try was with Dunkin Donuts.
As a happy coincidence (another one!) they have .99 cent ($1.07 with tax) iced coffees from 3 pm to 6 pm, and any size! I picked a small, iced coffee with milk and sugar.
Although there's a little bitter edge to the coffee, it's watered down and milkified enough (but not too much!), so it hasn't given me heartburn or other gastric distress. These gastric issues lie behind my not having ingested coffee products in over 5-6 years!
So I liked the Dunkin Donuts iced coffee because it's a damn cheap deal and I can palate the taste.

The second try was a Starbucks tall iced coffee with milk and sugar (for $2.11 with tax).
I don't like the smell of coffee emanating in Starbucks stores because it smells bitter, or burnt, to me. I had a taste of a cappuccino in 2001 in an Italian (Liguria region) coffee-bar with my maternal grandmama, and it was the smoothest coffee taste I'd ever tasted.
Back to the Starbucks. It's darker in color than the Dunkin Donuts, indicating a higher coffee content (and caffeine!) than the DD, however, the bitter edge is somewhat tempered by being a smidge sweeter than DD's. I can't say I liked this one, sorry folks.

The final, unintended comparison test was when I put an old DD cup next to the tall Starbucks. The Starbucks was a tad smaller than the DD. I think DD is the winner in this round of the taste test.

Do you have a favorite iced coffee concoction?